Add pulse support to the PennyLane-Braket plugin for the OQC device

[lillian542]

Description of changes:
Adds access to the OQC device Lucy through PennyLane's pulse programming module.

Where it was simple to do so, the code was kept general for ease of adding additional devices later. However, some refactoring to remove hardcoded assumptions based on the Lucy device will certainly be necessary to add additional pulse-based devices.

• adds ParametrizedEvolution as an allowed operation for the OQC Lucy device only
• adds a dispatch of _translate_operation for converting a PennyLane ParameterizedEvolution to a Braket PulseGate
  • to facilitate this, because device-specific information regarding frames is needed for translation, a device kwarg is added to _translate_operation, which defaults to None
• adds validation checks for parameters of the pulse where needed to ensure timely and clear error messages wrt invalid pulse inputs
• adds a pulse_settings attribute (user-facing) that retrieves and displays some of the device specs (resonant frequency, connectivity, anharmonicity) that users might want in PL simulations
  • to facilitate this, several helper-functions are added to retrieve frame names rather than hardcoding them to use the Lucy format

Open questions:

• Should a warning be raised if a user provides settings to use with a pulse to inform them that the settings will be ignored? Raising a warning would be inconsistent with vanilla PennyLane behaviour.

Testing done:

• unit testing of the _translate_operation function for both constant amplitudes and amplitudes with a callable defining a pulse envelope
• unit testing for the pulse_settings and the functions to access device frames
• unit testing for errors raised in validation for invalid ParametrizedEvolution operators

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