trace based block for non existing block

[FlorianHuc]

Description

create an endpoint to generate a trace for an invalid block

Tasks

• define the RPC format. Input required are: block number, list of transaction, TBC coinbase address
• use the state of the parent block, and generate a trace for a virtual block that would reuse the same timestamp, block number randao, ... as block from input parameter and that contains the list of trasnaction from the parameters.

Acceptance criteria

• the generated trace can be used to generate a proof
• state of the tracer instance is not modified