✨ Upgrade Diagnosis Capabilities

[DRovara]

Description

This pull request improves the diagnosis capabilities, in particular, how it interprets the uses of variables:

• We now recognise the uses of variables inside custom gate calls. E.g. data dependencies now spread into the contents of custom gates.
• This includes a better analysis of substitutions. Renamings of variables through custom gate calls are now covered.
• Compact gate calls on full registers are now also understood. E.g. in the code qreg q[2]; x q; h q[0]; we can now recognise the data dependency between x q and h q[0] even though the variable is not exactly equal.

This pull request also introduces several new test to check these features.

Checklist:

• The pull request only contains commits that are related to it.
• I have added appropriate tests and documentation.
• I have made sure that all CI jobs on GitHub pass.
• The pull request introduces no new warnings and follows the project's style guidelines.

[codecov-commenter]

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Codecov Report

Attention: Patch coverage is 99.08257% with 2 lines in your changes missing coverage. Please review.

Project coverage is 98.7%. Comparing base (fc5c418) to head (3285634).

Files with missing lines	Patch %	Lines
src/backend/dd/DDSimDebug.cpp	98.2%	1 Missing ⚠️
src/backend/dd/DDSimDiagnostics.cpp	99.0%	1 Missing ⚠️

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Additional details and impacted files

@@           Coverage Diff           @@
##            main     #20     +/-   ##
=======================================
+ Coverage   98.5%   98.7%   +0.2%     
=======================================
  Files          9       9             
  Lines       1399    1582    +183     
  Branches     241     289     +48     
=======================================
+ Hits        1379    1563    +184     
+ Misses        20      19      -1     

Flag	Coverage Δ
cpp	98.7% <99.0%> (+0.2%)	⬆️
python	100.0% <ø> (ø)

Files with missing lines	Coverage Δ
src/common/parsing/CodePreprocessing.cpp	98.6% <100.0%> (+0.1%)	⬆️
src/common/parsing/Utils.cpp	100.0% <100.0%> (ø)
src/backend/dd/DDSimDebug.cpp	98.4% <98.2%> (+0.2%)	⬆️
src/backend/dd/DDSimDiagnostics.cpp	99.6% <99.0%> (+0.2%)	⬆️