braket measurement fix, qiskit, pyquil initial_qubit_mapping fix

[vishal-ph]

Description

• Updates/ Changes to the measurement instructions on the braket backend to selectively measure a subset of all qubits in the circuit.
• Some fixes to other backends including qiskit and pyquil that came up

[vishal-ph]

NOTE: The changes made to the braket backend require extensive testing that still needs to be planned. In general, testing the mechanism for non-trivial measurement instructions requires access to QPUs or QPU emulators, or may require some other trick to accomplish.
WORK IN PROGRESS