♻️ Refactor handling of Barrier operations

[burgholzer]

Description

This commit refactors how the Barrier operations are handled across the operations, moving it from non-unitary operations to the standard operations. The changes include updates in the display of the barriers and how they are parsed in the QASMParser, along with modifications in the operation files and test files. This change improves code structure allowing a more consistent handling of operations. Barriers are essentially No-Ops, so there is no reason for them to be non-unitary.

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.

[github-actions]

Cpp-Linter Report ✔️

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[codecov]

Codecov Report

Merging #394 (ea3842e) into main (5982ba7) will increase coverage by 0.0%.
The diff coverage is 92.7%.

@@          Coverage Diff          @@
##            main    #394   +/-   ##
=====================================
  Coverage   89.2%   89.3%           
=====================================
  Files         98      98           
  Lines      11661   11655    -6     
  Branches    2090    2087    -3     
=====================================
+ Hits       10411   10413    +2     
+ Misses      1250    1242    -8     

Files Changed	Coverage Δ
include/operations/OpType.hpp	89.4% <ø> (ø)
src/operations/StandardOperation.cpp	93.2% <75.0%> (+0.4%)	⬆️
src/CircuitOptimizer.cpp	85.1% <92.3%> (+1.0%)	⬆️
include/QuantumComputation.hpp	93.8% <100.0%> (-0.1%)	⬇️
include/operations/NonUnitaryOperation.hpp	100.0% <100.0%> (ø)
include/operations/Operation.hpp	94.9% <100.0%> (+0.1%)	⬆️
src/QuantumComputation.cpp	76.8% <100.0%> (ø)
src/operations/NonUnitaryOperation.cpp	94.7% <100.0%> (-0.6%)	⬇️
src/operations/Operation.cpp	89.8% <100.0%> (+0.3%)	⬆️
src/parsers/QASMParser.cpp	97.8% <100.0%> (ø)

... and 1 file with indirect coverage changes