Implement get_import _path

[Gallaecio]

I think we should do the following:

Deprecate scrapy.utils.python.get_global_object in favor of a new function named get_import_path, and replace all usages.

Make the argument of get_import_path a positional-only argument, since obj could be a confusing name when passing a class (class instances are not supported).

Find uses of __module__, __name__, and __qualname__, and where appropriate replace them with the new function.

However, we should probably discuss this before someone starts implementing it. Maybe this should be implemented elsewhere, or we should choose a different naming or implementation.