Later in the stack, further code will check and inform the user that var names must start with a letter
or underscore, so this fix only allows us to get to that previously existing policy.
Fixes#16008
* attempt #11 to role_include
* fixes from jimi-c
* do not override load_data, move all to load
* removed debugging
* implemented tasks_from parameter, must break cache
* fixed issue with cache and tasks_from
* make resolution of from_tasks prioritize literal
* avoid role dependency dedupe when include_role
* fixed role deps and handlers are now loaded
* simplified code, enabled k=v parsing
used example from jimi-c
* load role defaults for task when include_role
* fixed issue with from_Tasks overriding all subdirs
* corrected priority order of main candidates
* made tasks_from a more generic interface to roles
* fix block inheritance and handler order
* allow vars: clause into included role
* pull vars already processed vs from raw data
* fix from jimi-c blocks i broke
* added back append for dynamic includes
* only allow for basename in from parameter
* fix for docs when no default
* fixed notes
* added include_role to changelog
This is unsafe and we debated re-adding it to the v2/2.0 codebase,
however it is a common-enough feature that we will simply mark it
as deprecated for now and remove it at some point in the future.
Fixes#11718