Check `op.has_matrix` before decomposing unsupported gates to QubitUnitary

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Context: We currently don't check if an unsupported controlled operation has a matrix and always prefer applying the operation as a QubitUnitary over PL's decomposition rules. As the result applying the controlled operations like TrotterProduct is not supported in Catalyst. This PR fixes the issue by checking operation.has_matrix before trying to generate & use the unitary matrix.

Description of the Change:

Update the decompostion method in the frontend
Add a unit test for ctrl(TrotterProduct)

Benefits: Support control of gates without matrix. For example, QJIT compiling ctrl(TrotterProduct) would throw the following compiler error without the proposed patch:

E           catalyst.utils.exceptions.CompileError: Operation Controlled(TrotterProduct(0.25, 0.75, 2.4, wires=[0]), control_wires=[1]) could not be decomposed, it might be unsupported.

Possible Drawbacks:

Related GitHub Issues: [sc-66427]

PennyLaneAI / catalyst

Check `op.has_matrix` before decomposing unsupported gates to QubitUnitary #831

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