style(capability)!: update go doc comments and remove BeginBlocker (cosmos#9845)

## Description

+ Backported go doc comment updates from cosmos#9835
+ Removed BeginBlocker function which only wraps the `InitMemStore` -> https://github.com/cosmos/cosmos-sdk/pull/9835/files#r681987005  -- this is not a breaking change because RC3 was not yet released.
+ Updated changelog

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [x] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [x] provided a link to the relevant issue or specification
- [x] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [x] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [x] added a changelog entry to `CHANGELOG.md`
- [x] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [x] updated the relevant documentation or specification
- [x] reviewed "Files changed" and left comments if necessary
- [x] confirmed all CI checks have passed

### Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

Author: robert-zaremba

CHANGELOG.md

@@ -54,7 +54,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (client/keys) [\#9407](https://github.com/cosmos/cosmos-sdk/pull/9601) Added `keys rename` CLI command and `Keyring.Rename` interface method to rename a key in the keyring.
 * (x/slashing) [\#9458](https://github.com/cosmos/cosmos-sdk/pull/9458) Coins burned from slashing is now returned from Slash function and included in Slash event.
 * [\#9246](https://github.com/cosmos/cosmos-sdk/pull/9246) The `New` method for the network package now returns an error.
-* [\#9519](https://github.com/cosmos/cosmos-sdk/pull/9519) `DeleteDeposits` renamed to `DeleteAndBurnDeposits`, `RefundDeposits` renamed to `RefundAndDeleteDeposits` 
+* [\#9519](https://github.com/cosmos/cosmos-sdk/pull/9519) `DeleteDeposits` renamed to `DeleteAndBurnDeposits`, `RefundDeposits` renamed to `RefundAndDeleteDeposits`
 * (codec) [\#9521](https://github.com/cosmos/cosmos-sdk/pull/9521) Removed deprecated `clientCtx.JSONCodec` from `client.Context`.
 * (codec) [\#9521](https://github.com/cosmos/cosmos-sdk/pull/9521) Rename `EncodingConfig.Marshaler` to `Codec`.
 * [\#9418](https://github.com/cosmos/cosmos-sdk/pull/9418) `sdk.Msg`'s  `GetSigners()` method updated to return `[]string`.
@@ -63,7 +63,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [\#9432](https://github.com/cosmos/cosmos-sdk/pull/9432) `ConsensusParamsKeyTable` moved from `params/keeper` to `params/types`
 * [\#9576](https://github.com/cosmos/cosmos-sdk/pull/9576) Add debug error message to `sdkerrors.QueryResult` when enabled
 * [\#9650](https://github.com/cosmos/cosmos-sdk/pull/9650) Removed deprecated message handler implementation from the SDK modules.
-* (x/capability) [\#9836](https://github.com/cosmos/cosmos-sdk/pull/9836) Removed `InitializeAndSeal(ctx sdk.Context)` and replaced with `Seal()`.
+* (x/capability) [\#9836](https://github.com/cosmos/cosmos-sdk/pull/9836) Removed `InitializeAndSeal(ctx sdk.Context)` and replaced with `Seal()`. App must add x/capability to begin blockers which will assure that the x/capability keeper is properly initialized. The x/capability begin blocker must be run before any other module which uses x/capability.
 
 ### Client Breaking Changes
 

x/capability/abci.go

@@ -99,10 +99,11 @@ func (k *Keeper) Seal() {
 	k.sealed = true
 }
 
-// InitMemStore will initialize the memory store if the initialized flag is not set.
-// InitMemStore logic should be run in first `BeginBlock` or `InitChain` (whichever is run on app start)
-// so that the memory store is properly initialized before any transactions are run.
-// InitMemStore also asserts the memory store type is correct, and will panic if it does not have store type of `StoreTypeMemory`.
+// InitMemStore will assure that the module store is a memory store (it will panic if it's not)
+// and willl initialize it. The function is safe to be called multiple times.
+// InitMemStore must be called every time the app starts before the keeper is used (so
+// `BeginBlock` or `InitChain` - whichever is first). We need access to the store so we
+// can't initialize it in a constructor.
 func (k *Keeper) InitMemStore(ctx sdk.Context) {
 	memStore := ctx.KVStore(k.memKey)
 	memStoreType := memStore.GetStoreType()
@@ -137,7 +138,7 @@ func (k *Keeper) InitMemStore(ctx sdk.Context) {
 	}
 }
 
-// IsInitialized returns true if the initialized flag is set, and false otherwise
+// IsInitialized returns true if the keeper is properly initialized, and false otherwise.
 func (k *Keeper) IsInitialized(ctx sdk.Context) bool {
 	memStore := ctx.KVStore(k.memKey)
 	return memStore.Get(types.KeyMemInitialized) != nil

x/capability/keeper/keeper.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"math/rand"
+	"time"
 
 	"github.com/gorilla/mux"
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
@@ -14,6 +15,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/codec"
 	cdctypes "github.com/cosmos/cosmos-sdk/codec/types"
+	"github.com/cosmos/cosmos-sdk/telemetry"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
 	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
@@ -143,8 +145,12 @@ func (am AppModule) ExportGenesis(ctx sdk.Context, cdc codec.JSONCodec) json.Raw
 func (AppModule) ConsensusVersion() uint64 { return 1 }
 
 // BeginBlock executes all ABCI BeginBlock logic respective to the capability module.
+// BeginBlocker calls InitMemStore to assert that the memory store is initialized.
+// It's safe to run multiple times.
 func (am AppModule) BeginBlock(ctx sdk.Context, _ abci.RequestBeginBlock) {
-	BeginBlocker(ctx, am.keeper)
+	defer telemetry.ModuleMeasureSince(types.ModuleName, time.Now(), telemetry.MetricKeyBeginBlocker)
+
+	am.keeper.InitMemStore(ctx)
 }
 
 // EndBlock executes all ABCI EndBlock logic respective to the capability module. It