keycloak_user_federation: sort desired and after mappers by name (#8761)
* sort desired mappers by name
* sort mappers fetched after update by name
* only sort mapper list if there are desired mappers specified
* add fallback `''` in case `name` is not a key or `None` when sorting mappers
* add changelog fragment
(cherry picked from commit 982b8d89b7)
Co-authored-by: fgruenbauer <gruenbauer@b1-systems.de>
