Include all gates in simulator targets

[speller26]

Summary

• Simulator targets now include all gates, regardless of qubit count
• Major refactor to make code more readable, with functions being extracted as appropriate
• Adds the device qubit count to the target.

Details and comments

Prior to this change, simulator targets and QPU targets alike were limited to up to 2q gates. Although no Braket devices are subject to these restrictions, this restriction still makes sense for QPUs because there is no analog of coupling map (and corresponding properties) for 3+ qubits. However, Braket simulators do not have a notion of coupling map, and gates can be applied to any qubit without impacting result quality. As such, this change removes this restriction for simulators.

[jcjaskula-aws]

LGTM