Implement re-designed Wasmi br_table instructions

[Robbepop]

This new br_table design fixes a pathological encoding scheme with the old br_table instruction when the branches required to copy values into different branch destination registers. The new design no longer has this pathological translation case and thus should use a lot less encoding space and be more efficient in some cases.

The downside is that this increased complexity in both, the Wasmi translator and also in the Wasmi bytecode executor to some extend. However, it could also be argued that the translation of the new br_table instructions is a bit simpler overall since the pathological case no longer has to be handled.

TODO

• Properly emit Instruction::BranchTableTargetNonOverlapping in cases where possible.
• Write missing docs for the new definitions.
• New Wasmi translation unit tests featuring the new encoding schemes.

[codecov]

Codecov Report

Attention: Patch coverage is 86.01695% with 99 lines in your changes missing coverage. Please review.

Project coverage is 79.76%. Comparing base (8c9f031) to head (36d197f).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/wasmi/src/engine/executor/instrs/branch.rs	38.70%	38 Missing ⚠️
crates/wasmi/src/engine/executor/instrs/copy.rs	26.08%	17 Missing ⚠️
crates/wasmi/src/engine/translator/mod.rs	92.89%	15 Missing ⚠️
crates/wasmi/src/engine/executor/instrs.rs	47.61%	11 Missing ⚠️
...ates/wasmi/src/engine/translator/visit_register.rs	0.00%	9 Missing ⚠️
crates/wasmi/src/engine/bytecode/utils.rs	0.00%	4 Missing ⚠️
crates/wasmi/src/engine/executor/instrs/return_.rs	60.00%	4 Missing ⚠️
...rates/wasmi/src/engine/translator/instr_encoder.rs	97.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1158      +/-   ##
==========================================
+ Coverage   79.62%   79.76%   +0.14%     
==========================================
  Files         296      296              
  Lines       25533    25952     +419     
==========================================
+ Hits        20331    20701     +370     
- Misses       5202     5251      +49     

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