feature: add support for braket measure instruction

[ashlhans]

Summary

Add support for Braket's measure instruction.

This solves the bug detailed in Issue #130 where translating a circuit in qiskit to braket returned all the measurements instead of the requested measured qubit.

Details and comments

Now, users can measure a subset of qubits on local simulators or any device that supports partial measurement.

Example:

sim = BraketLocalBackend()
qc = QuantumCircuit(2, 1)
qc.h(0)
qc.cx(0, 1)
qc.measure(0, 0)
task = transpile(qc, sim)
task = sim.run(task)
result = task.result()
counts = result.get_counts()
print(counts)

{'1': 518, '0': 506}

To keep the current functionality of the bug and measure all the qubits, simply change measure(0, 0) to measure_all()

sim = BraketLocalBackend()
qc = QuantumCircuit(2, 1)
qc.h(0)
qc.cx(0, 1)
qc.measure_all()
task = transpile(qc, sim)
task = sim.run(task)
result = task.result()
counts = result.get_counts()
print(counts)

{'00': 503, '11': 521}

List of changes

• Update the amazon-braket-sdk version
• add measure to the Braket gates
• update adapter.py to use Braket's measure
• add tests

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