Improve user feedback when creating new Table View (user forgets setting Table Topic Type)

I tested with DMX 5.0 beta 7 and dmx-tableview-0.4.0_2020-04-16_9712.

When the user wants to create a new Table View he/she opens the search/create dialogue and enters a name for the new Table View. The user will then select "Table View" from the Topic Type menu.

If the user now clicks "create" before selecting a "Table Topic Type" the following exceptions is thrown:

500 Server Error { "exception": "org.codehaus.jettison.json.JSONException", "message": "JSONObject["tableTopicType"] not found." }

Possible improvements : Either present a user-readable message like "Select a Table Topic Type first" or enable the "create" button only when user has selected the necessary values from both dropdown menus.