feat: ✨ numpy-array-use-type-var flag

[ringohoffman]

Fixes #187

Adds the flag --numpy-array-use-type-var which reformats the pybind11-generated numpy.ndarray[numpy.float32[m, 1]] annotation as numpy.ndarray[tuple[M, Literal[1]], numpy.dtype[numpy.float32]] using TypeVars; this allows for type-checker supported shape checking

Notable changes are:

• The addition of FixNumpyArrayDimTypeVar, corresponding to the --numpy-array-use-type-var flag
• TypeVar_ struct (appended _ to avoid conflicting with from typing import TypeVar), and new Module.type_vars field
• FixTypingTypeNames.parse_annotation_str() was extracted into a helper method so that it could be additionally be called on every item of result.parameters in order to expand the Literal inside the result.parameters into e.g. typing_extensions.Literal
• FixScipyTypeArguments was added to remove type arguments from anything from scipy.sparse, since they are not generic and do not accept any type arguments; the shape annotations provided by --numpy-array-wrap-with-annotated are left intact
• FixNumpyDtype forces numpy.dtype without parameters to be numpy.dtype[typing.Any] since it expects one type argument

[ringohoffman]

Let me know what you want to do in the way of testing this. Does it make sense to create another set of sub-folders under each of tests/stubs/python-*/pybind11-master?

• tests/stubs/python-3.7/pybind11-master/numpy-array-wrap-with-annotated
• tests/stubs/python-3.7/pybind11-master/numpy-array-use-type-var

?

Would we loop over these flags in tests/check-demo-stubs-generation.sh?

[sizmailov]

Does it make sense to create another set of sub-folders under each of tests/stubs/python-*/pybind11-master?

* `tests/stubs/python-3.7/pybind11-master/numpy-array-wrap-with-annotated`

* `tests/stubs/python-3.7/pybind11-master/numpy-array-use-type-var`

Unfortunately yes. Let's limit the tests for numpy-array-use-type-var to the latest pybind11 and python.

Would we loop over these flags in tests/check-demo-stubs-generation.sh?

No, let's add an extra command line option to check-demo-stubs-generation.sh for the numpy array transformation.
Let's create a separate entry for numpy-array-use-type-var in gh-actions yml.

[ringohoffman]

I gave it my best effort! Please let me know what you would have me change!

[sizmailov]

Thanks! Looks good to me!

The last minor thing. Let's make the CI job name for numpy-array-use-type-var different from the default one.

[sizmailov]

Many thanks for contribution. I'll publish it as v2.4

[ringohoffman]

Does this affect the status of #113 or #115?

[sizmailov]

Indeed, #115 could be closed.
I think #113 is not affected, since nptyping uses its own types.