feat: Add gate modifiers and additional supported gates to AutoQASM

[rmshaffer]

Issue #, if available:
Gate modifier support in AutoQASM: #957
Support U, GPhase, PRx gates in AutoQASM

Description of changes:
Add support for three additional keyword arguments to AutoQASM gates, for consistency with the Circuit class and associated gates (see #562):

• control: QubitIdentifierType | Iterable[QubitIdentifierType] | None = None
• control_state: BasisStateInput | None = None
• power: float | None = None

Also add the gphase, u, and prx gate definitions for consistency with the main Braket SDK (see #799, #945).

Testing done:
tox passes. Tests added to cover new functionality.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (72af596) to head (799891b).

Additional details and impacted files

@@                Coverage Diff                 @@
##           feature/autoqasm      #958   +/-   ##
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  Coverage            100.00%   100.00%           
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  Files                   173       172    -1     
  Lines                 10589     10568   -21     
  Branches               2264      2261    -3     
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- Hits                  10589     10568   -21     

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[ajberdy]

Could be interesting to think of alternatives, like

aq.ctrl([0, 1], "10") @ aq.pow(0.123) @ t(2)

or

# allows controlling logical chunks of a program 
# (can we distribute the op effectively?)
with aq.ctrl(0):
    t(1)

[rmshaffer]

I agree that there may be a more clever syntax for this. The approach in this PR is most consistent with what the Braket SDK does today (and also happens to be the easiest to implement, given how OQpy implements control modifiers). But we should keep thinking about this and consider whether there's something nicer to do.

[laurencap]

Is this logic duplicated in the BDK? I suppose the risk of it changing / getting out of sync is pretty minuscule if there's no bugs

[rmshaffer]

Yes, it's a duplicate of the logic here:

amazon-braket-sdk-python/src/braket/circuits/instruction.py

Lines 98 to 101 in 395662e

	self._control_state = BasisState(
	(1,) * len(control_set) if control_state is None else control_state,
	len(control_set),
	)

It would be difficult to re-use directly since we don't use the BDK Instruction class in AutoQASM. I do agree that the duplication is not ideal, but it seems very low-risk.