Create a `measured_wires` property on `QuantumScript`

[antalszava]

Feature details

Some features require knowledge about all the wires being measured on a quantum script (e.g., serialization to OpenQasm format). Furthermore, this information might be useful for devices (e.g., default.mixed already uses this).

There could be a measured_wires property in the QuantumScript class that gathers the measured wires. Approaches to collecting these wires only on demand should be considered along with caching.

Implementation

No response

How important would you say this feature is?

1: Not important. Would be nice to have.

Additional information

No response

[comp-phys-marc]

I have a pull request addressing this issue here: https://github.com/PennyLaneAI/pennylane/pull/3655.