fix: Compatibility layer will prefer to return `DelayFrames`, then `DelayQubits`, then `Delay`.

[mac01021]

Description

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Checklist

• [ ] The PR targets the master branch
• [ ] The above description motivates these changes.
• [ ] The change is atomic and can be described by a single commit (your PR will be squashed on merge).
• [ ] All changes to code are covered via unit tests.
• [ ] Parameters and return values have type hints with PEP 484 syntax.
• [ ] Functions and classes have useful Sphinx-style docstrings.
• [ ] (New Feature) The docs have been updated accordingly.
• [ ] (Bugfix) The associated issue is referenced above using auto-close keywords.