[typescript] Use static middleware when calltime options exist but specify no middleware

[bodograumann]

This PR is a continuation of #20978 with more improvements following #20430.
I'll rebase once the other PR is merged. Currently this branch contains all changes from both PRs.

• Keep static middleware when options contain no middleware field
  This is the main change in behaviour as discussed before in the other PR.
  When the user calls a method with options that do not set a middleware, the existing static middleware should be used, to follow the spirit of merging the top-level fields of the options.
  On the other hand the user can give an empty array to skip any middlewares for the call.
  I added tests for both cases.
• Extract middleware merge logic into function
  I included more refactoring in this PR.
• Simplify extracted functions
• Fix: Pass static config when no options are given for inversify
  I also noticed an error in the inversify variant. When no options are given, the static config should be used. Previously even empty options where used here.
  Unfortunately it seems the inversify tests are broken and I guess inversify 6 is not compatible with typescript 4. Anyway I could not get them to work again and so I did not add a test here.
• Fix: Allow overriding http api with options
  Another bug, that I found, is that httpApi was always taken from the static configuration and could not be overridden using options. I fixed that and added a test.
• Regenerate samples
  I regenerated the samples after almost every change, to make them clearer.

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CC @TiFu (2017/07) @taxpon (2017/07) @sebastianhaas (2017/07) @kenisteward (2017/07) @Vrolijkx (2017/09) @macjohnny (2018/01) @topce (2018/10) @akehir (2019/07) @petejohansonxo (2019/11) @amakhrov (2020/02) @davidgamero (2022/03) @mkusaka (2022/04) @joscha (2024/10)

[bodograumann]

I rebased all remaining changes here onto master, @joscha .
Is that small enough, or should I split it up?
There are multiple things happening here:

• Format change
• Refactor to improve code
• Slight behavioural change
• Two bug fixes

[joscha]

can this become a signature change, i.e.: ..., strategy: "append" | "prepend" | "replace" = "append" then the default is also visible for callers.

[bodograumann]

Good idea. Changed :-)

[joscha]

did you move this out because of the explicit return rule? Otherwise I think it was semantically easier to understand inside the switch.

[bodograumann]

It felt cleaner to me, because it made it obvious, that it is a last-resort for the function (actually in typescript it is unreachable anyway, because the switch completely covers all possible values of strategy)
Putting it into default makes sense as well because it is concerned with invalid values for strategy.
I can put it back into default: if you prefer.

[joscha]

I'd prefer it for future readers/changes, to make sure noone puts code in between. It should immediately exit on an unknown value. If you're happy to move it back in, that would be appreciated.

[bodograumann]

Makes sense. I moved it back inside.

[joscha]

@macjohnny this one is ready, too