dcnm_fabric: Add support for IPFM fabrics (ready for review)

[allenrobel]

This commit adds the following:

1. Support for IP Fabric for Media fabrics.
2. ControllerFeatures() class to retrieve admin and oper state of NDFC features.
3. FabricTypes() add FABRIC_TYPE to feature mapping.
   • Maps FABRIC_TYPE to the NDFC feature (e.g. "vxlan", "pmn") required to be enabled for that FABRIC_TYPE
4. A standardized and shareable set of classes for retrieving NDFC REST API endpoints
   • This currently contains enough for the ControllerFeatures() class
   • We can add more in the future

NDFC REST API endpoint retrieval looks something like:

from ansible_collections.cisco.dcnm.plugins.module_utils.common.api.v1.fm import \
    Features, Version

api_features = Features()
api_version = Version()
controller_features_response = dcnm_send(module, api_features.verb, api_features.path)
controller_version_response = dcnm_send(module, api_version.verb, api_version.path)
# etc...