Make Add-DbaDbRoleMember show a warning if user not found
Make Add-DbaDbRoleMember show a warning if user not found

If Add-DbaDdbRoleMember is called to add a user to a database role, but that user doesn't have a login the call fails silently. Have changed the message from Verbose to Warning to make this more obvious.
kozloski/dbatools,wsmelton/dbatools