New Web UI forms for Murano 0.5 with new DSL

Custom form fields will be introduced in Murano 0.5 UI: where we currently have hardcoded field types like integer, string, clusterip or image, new field types will be allowed, like 'com.mirantis.windows.ActiveDirectory' (note that here we take an advantage of fully qualified service name) - and such fields will be rendered in a special way.

So, the field will consist of:
* a drop-down box (to the left), where all the services of such type already created in current environment will be listed
* and a '+' button (to the right) which, if pressed, opens new modal form window with all steps required for creation of that service upon. Right after last creation step is finished, newly configured service will be chosen in a drop-down box.