Allow autodetection of qubit count #118
Description
Input programs may optionally provide metadata that indicates the number of qubits that is required for the program to run. For example, this is available in QIR metadata and may be available in HUGR metadata if it has been provided by the user.
At the moment, we require n_qubits as an integer argument to run and run_shots. We should make this optional, defaulting to None. If None is provided, we can fall back to whatever information we can gather from the input program - if none is available, we raise an exception.
Selene itself doesn't see the input program - it instead sees the program after having been compiled to the appropriate interface (e.g. helios-qis). It also sees the selene yaml file that acts as a manifest of the build. It would be appropriate for us to encode metadata within this manifest, or elsewhere, from the selene-core build system in order for selene-sim to read it.
This is also the opportunity to inject any other metadata we wish to extract and utilise. Suggestions welcome!