feat: add parameterized QASM3 exporter

[nathandelcid]

Closes #146.

Summary

Moves OpenQASM 3 export out of QuantumCircuit into the header-only Qiskit::qasm3::dumps API. The existing exporter already serialized symbolic parameter expressions using qk_param_str, but the generated OpenQASM was invalid because free parameters were not declared. Parameterized exports can now supply ordered parameter names, which are emitted as input float[64] declarations. The parameter names must be supplied explicitly because the current Qiskit C API exposes the number of free symbols but cannot enumerate their names.

Details and comments

• Adds Qiskit::qasm3::dumps(circuit) for circuits without free parameters.
• Adds Qiskit::qasm3::dumps(circuit, input_parameters) for parameterized circuits.
• Removes QuantumCircuit::to_qasm3().
• Preserves existing unparameterized QASM output.
• Validates missing, extra, empty, and duplicate parameter names.
• Uses RAII wrappers to clear C API instruction and operation-count allocations.
• Updates existing samples, providers, primitives, tests, tutorial, and release notes.
• Keeps the exporter header-only and requires no CMake changes.

Testing

• CTest: 3/3 tests passed on Windows with MSVC.
• All locally configured sample targets built successfully with MSVC.
• GCC C++11 syntax checks passed for the exporter test translation units.
• Tutorial notebook JSON validation passed.
• Doxygen was not run because it is not installed locally.

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• I have added the tests to cover my changes.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.

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Portions of this pull request were generated or modified with the help of OpenAI Codex (GPT-5.5). Changes were reviewed and validated by human developer @nathandelcid

[CLAassistant]

All committers have signed the CLA.