Includes:
- Extensive changes to "mapping roles" section
- New section for role mapping API
- Updates to LDAP/AD/PKI realms to refer to API based role mapping
- Updates to LDAP/AD realms: `unmapped_groups_as_roles` only looks at file-based mappings
- Updates to LDAP/AD realms: new setting for "metadata"
Original commit: elastic/x-pack-elasticsearch@6349f665f5
When the active directory realm was refactored to add support for authenticating against multiple
domains, only the default authenticator respected the user_search.filter setting. This commit moves
this down to the base authenticator and also changes the UPN filter to not include sAMAccountName
in the filter.
Original commit: elastic/x-pack-elasticsearch@d2c19c9bee