Change the way multiple values for dynamic UI 'type' attr are parsed

* Pass multiple values for 'type' as normal YAML sequence, not string.
* Add emptyValueMessage attribute to such fields. It will be used as a
  description of initial empty value.
* Deprecate 'domain' type - io.murano.windows.ActiveDirectory should be
  used instead (use openstack.common.versionutils.deprecated).

Targets: blueprint dynamic-ui-deprecate-obsolete-fields
Change-Id: I451ce0282910d36b3040a96b2380de348e6bdb53