Serialize QuantumDevice (QAE-807)

Explanation of changes

Serialize the QuantumDevice by adding __getstate__ and __setstate__ methods to the class.

Notes:

• Introduce the private attribute self._deserialized_instruments (dict), to store instruments after deserialization and prevent double instrument instantiation. Instruments are obtained through self.extract_deserialized_instruments()
• Generalized ScheduleJSONEncoder(Decoder) to SchedulerJSON…
• Update QuantumDevice serialization in the bug report

Motivation of changes

QuantumDevice is a fundamental piece of information for reproducing experiments, but at the moment it cannot be serialized.

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Merge checklist

See also merge request guidelines

• Merge request has been reviewed (in-depth by a knowledgeable contributor), and is approved by a project maintainer.
• New code is covered by unit tests (or N/A).
• New code is documented and docstrings use numpydoc format (or N/A).
• New functionality: considered making private instead of extending public API (or N/A).
• Public API changed: added @deprecated (or N/A).
• Newly added/adjusted documentation and docstrings render properly (or N/A).
• Pipeline fix or dependency update: post in #software-for-developers channel to merge main back in or update local packages (or N/A).
• Tested on hardware (or N/A).
• CHANGELOG.md and AUTHORS.md have been updated (or N/A).
• Windows tests in CI pipeline pass (manually triggered by maintainers before merging).
  • Maintainers do not hit Auto-merge, we need to actively check as manual tests do not block pipeline

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For reference, the issues workflow is described in the contribution guidelines.