Create a generic helper class in module_utils to parse
inventory yaml. Similar to the ansible-core InventoryManager
but usable from ansible modules with minimal dependencies
(just python stdlib and yaml).
This should be compatible with any current/past tripleo inventory
structures and potentially future inventory structure changes (within
reason).
Related-bug: #1998649
Change-Id: Id2fb39054bd5f81deb967ed9938c613a2ca6ea2c
92c59b3f99