ldap docker image: provide script to assign an existing user permissions to manage accounts

[gunterze]

Provide script to assign an user initialized by Keycloak 11 or older version permissions to manage accounts necessary after upgrade to Keycloak 12+.

$ docker exec ldap init-account
Usage: init-account USER [OPTIONS]

init-account initiate persisted Role Mappings for Keycloaks Account Management,
assigning USER roles for managing it account.

OPTIONS:
       -n     Show what would be done, but don't actually add entries.  Useful for debugging in conjunction with -v.
       -v     Use verbose mode, with many diagnostics written to standard output.
       -c     Continuous operation mode.  Errors are reported, but init-account will continue with modifications.  The default is to exit after
              reporting an error.

and

$ docker exec ldap add-account
Usage: add-account USER [OPTIONS]

add-account updates persisted Role Mappings for Keycloaks Account Management, assigning USER required roles for managing it accounts.

OPTIONS:
       -n     Show what would be done, but don't actually modify entries.  Useful for debugging in conjunction with -v.
       -v     Use verbose mode, with many diagnostics written to standard output.
       -c     Continuous operation mode.  Errors are reported, but add-account will continue with modifications.  The default is to exit after
              reporting an error.