Fix wires in definitions

[thisac]

Context:
When definining an observable, the wires where seemingly not passed to the declaration unless explicitly declared.

>>> import xir
>>> program = xir.parse_script("obs Z: 1, Z[0]; end;")
>>> observable = program.declarations["obs"][0]
>>> observable.wires
()

Description of the Change:

• Wires are implicitly added to the declaration if not explicitly declared in a definition.
• The maximum wire value used in a statement within a definition will be the number of wires declared. E.g., if, within a definition, a single statement is applied on wire 4, then the declared wires will be 0, 1, 2, 3, and 4.
• Validation now checks that applied wires is a subset of declared wires (they don't need to be equal).
• All definitions will have declared wires (either explicitly or implicitly).

Benefits:
Wires are now being declared correctly.

Possible Drawbacks:
The validation check for incorrectly using string wires without explicitly declaring wires is gone. Instead, integer wires are implicitly declare, causing applied wires with string labels to not be a subset of the declared wires.

program = xir.parse_script("gate foo[0, 1, 2]; gate bar: foo | [0, a]; end;")
val = xir.Validator(program)
val.run()

Output:

ValidationError: XIR program is invalid: the following issues have been detected:
	-> Definition 'bar' is invalid. Applied wires [0, a] differ from declared wires [0].

Related GitHub Issues:
None

[github-actions]

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Please edit .github/CHANGELOG.md with:

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[Mandrenkov]

Awesome! 🎉