Support parameter broadcasting with `GlobalPhase`

[dwierichs]

Context: GlobalPhase does not support broadcasting yet.

Description of the Change: Introduce broadcasting to GlobalPhase, using the code from PauliRot with set(pauli_word) == {"I"}. The latter falls back to the GlobalPhase implementation.

Benefits:

Possible Drawbacks:

Related GitHub Issues: Implements #5815

[sc-65316]