Fixes #29681 - Fixing bad regex for excluding facts

Foreman uses facts from many tools like Ansible or Puppet to gather
facts about hosts. These facts are also full of facts that foreman don't
care about. That's why Excluded facts setting exist. It has some bugs...

Fixes #31099 - filter out unstable facts: memory and load

Fixes #21654 - create registry for importers

Fixes #23072 - Fix fact importer transaction isolation

Fixes #26984 - maximum subtree fact filter

Fixes #27249 - flip the comma cop

Fixes #26852 - add disks exclude fact patterns

Fixes #19789 - fix Layout/SpaceAroundOperators cop

Fixes #20929 - Added fact name filtering on import

Added a setting that will filter out fact names, so they won't be
recorded into `fact_names` and `fact_values` tables at all.

Fixes #21776 - Improved fact importing to deal with names

Now the list of fact names will be calculated beforehand and saved
to the database. It will also consider that the name could be added
from other thread.