Don't obfuscate full module name when generating framework-specific API classes

Currently, we shorten/obfuscate the module name when dynamically generating our framework-specific public API classes. E.g. when we create AsyncIOMotorClient we do:

def create_asyncio_class(cls):

    return create_class_with_framework(cls, asyncio_framework, 'motor_asyncio')

AsyncIOMotorClient = create_asyncio_class(core.AgnosticClient)

with the factory function defined as:

def create_class_with_framework(cls, framework, module_name):

    motor_class_name = framework.CLASS_PREFIX + cls.__motor_class_name__

    cache_key = (cls, motor_class_name, framework)

    cached_class = _class_cache.get(cache_key)

    if cached_class:

        return cached_class

    new_class = type(str(motor_class_name), cls.__bases__, cls.__dict__.copy())

    new_class.__module__ = module_name

    new_class._framework = framework

    ...

    ...

Consequently, AsyncIOMotorClient appears to belong (as per its _module_ value) to the motor_asyncio module, even though it actually resides in motor.motor_asyncio. This creates problems when we attempt to use intersphinx to link to the MOTOR documentation as seen in MOTOR-338.

Unless there is a good rationale for fudging the _module_ of these classes, we should change the code so that it reflects the actual path.

ORIGINAL DESCRIPTION

In my conf.py I have:

extensions = [

    'sphinx.ext.autodoc',

    'sphinx.ext.autosummary',

    'sphinx.ext.intersphinx',

    'sphinx.ext.extlinks',

]

intersphinx_mapping = {

    'python': ('https://docs.python.org/3/', None),

    'motor': ('https://motor.readthedocs.io/en/stable/', None),

}

code.rst:

.. automodule:: code

    :members:

    :undoc-members:

    :show-inheritance:

code.py:

from asyncio.motor_asyncio import (    AsyncIOMotorClient, AsyncIOMotorDatabase, AsyncIOMotorCollection)

class MyClient(AsyncIOMotorClient):

    pass

class MyDatabase(AsyncIOMotorDatabase):

    pass

class MyCollection(AsyncIOMotorCollection):

    pass

Sphinx output:

code.py:docstring of code.MyClient:1: WARNING: py:class reference target not found: motor_asyncio.AsyncIOMotorClient
code.py:docstring of code.MyDatabase:1: WARNING: py:class reference target not found: motor_asyncio.AsyncIOMotorDatabase
code.py:docstring of code.MyCollection:1: WARNING: py:class reference target not found: motor_asyncio.AsyncIOMotorCollection

Adding a top-level module 'motor_asyncio' to the intersphinx configuration does not help.
References in the docstrings and .rst files to :class:`motor.motor_asyncio.AsyncIOMotorClient` work fine.