♻️ Refactor FoMaC classes

[MatthiasReumann]

Description

Proposed FoMaC rewrite:

• Use unique_ptr instead of custom destructor, copy, and move semantics.
• Remove trailing return types as the return type does not depend on the arguments.
• Remove "Tokens". Use private constructors and friendship semantics.
• Consistency improvements (std::size_t vs size_t, etc.)

Checklist

• The pull request only contains commits that are focused and relevant to this change.
• I have added appropriate tests that cover the new/changed functionality.
• I have updated the documentation to reflect these changes.
• I have added entries to the changelog for any noteworthy additions, changes, fixes, or removals.
• I have added migration instructions to the upgrade guide (if needed).
• The changes follow the project's style guidelines and introduce no new warnings.
• The changes are fully tested and pass the CI checks.
• I have reviewed my own code changes.

If PR contains AI-assisted content:

• I have disclosed the use of AI tools in the PR description as per our AI Usage Guidelines.
• AI-assisted commits include an Assisted-by: [Model Name] via [Tool Name] footer.
• I confirm that I have personally reviewed and understood all AI-generated content, and accept full responsibility for it.

[github-actions]

Cpp-Linter Report ⚠️

Some files did not pass the configured checks!

clang-tidy (v22.1.8) reports: 1 concern(s)

• src/na/fomac/Device.cpp:578:1: warning: [cppcoreguidelines-pro-type-member-init]

  constructor does not initialize these bases: Device

    578 | Session::Device::Device(const fomac::Device& device)
        | ^
    579 |     : fomac::Device(device), na::Device{} {}
        |       Device(),

Have any feedback or feature suggestions? Share it here.

[codecov]

Codecov Report

❌ Patch coverage is 95.83333% with 9 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
include/mqt-core/fomac/FoMaC.hpp	93.5%	7 Missing ⚠️
src/fomac/FoMaC.cpp	97.9%	2 Missing ⚠️

📢 Thoughts on this report? Let us know!