pyreverse: Add option to exclude standard library

[avylove]

Current problem

When creating class diagrams, there is no option to exclude imports from the standard library, which can add a lot of information that may not be completely relevant depending on what you're doing.

Desired solution

It would be good to add a CLI option to exclude standard library imports, similar to show-builtin: False for builtins.

Additional context

No response

[DudeNr33]

I agree, getting pyreverse diagrams into a usable sized format is hard, so I would fully support this feature if someone wants to contribute a pull request for this!