* Move get_all_subclasses out of sys_info as it is unrelated to system
information.
* get_all_subclasses now returns a set() instead of a list.
* Don't port get_platform to sys_info as it is deprecated. Code using
the common API should just use platform.system() directly.
* Rename load_platform_subclass() to get_platform_subclass and do not
instantiate the rturned class.
* Test the compat shims in module_utils/basic.py separately from the new
API in module_utils/common/sys_info.py and module_utils/common/_utils.py
* Move ansible.compat.tests to test/units/compat/.
* Fix unit test references to ansible.compat.tests.
* Move builtins compat to separate file.
* Fix classification of test/units/compat/ dir.
* Separate networking tools that may be used by modules outside of networking so changes to networking-only utilities don't trigger AWS integration tests
* Add unit tests for moved network utils
* Add comment to prevent imports from being mistakenly removed
* Move to_bits as well
Move dict_merge from azure_rm_resource module to
module_utils.common.dict_transformations and add tests.
Use dict_merge to provide a fairly realistic, reliable
diff output when k8s-based modules are run in check_mode.
Rename unit tests so that they actually run and reflect
the module_utils they're based on.
