Allow @deprecate_arg predicate to also normalize the argument's value

[Eric-Arellano]

There are a few cases where deprecated argument data types get normalized. Currently, we end up duplicating the code to detect if it's a bad data type so that we can a) issue the warning via @deprecate_arg and b) normalize the data inside the body of the function. See #9897 (comment) for an example.

It would be useful if we could have predicate also normalize the data. I'm thinking we have it update the *args and **kwargs passed to the original function, which we already have precedent of doing with new_alias:

https://github.com/Qiskit/qiskit-terra/blob/751fa46947aa1cc581b0fc25673236e396397b0f/qiskit/utils/deprecation.py#L294-L295

We probably want predicate to have the return type of bool | tuple[bool, Any]. That is, you can still simply return a bool if it's normalized or not. Or, you can return the bool + the normalized value.

[Eric-Arellano]

Imo this is low priority. It would still be neat, but seems unlikely we'll get to this. Feel free to reopen if others disagree.