Always displays the View properties tab when an advanced mode is configured in a widget

After filling the field "Advanced mode configuration", it is possible to configure the View properties of a widget in Edit layout. But the View properties tab disappears when the widget is saved and edited again.

Steps to reproduce:

1. Add a Single directory suggestion widget in the Edit layout
2. Observe that only the Edit properties tab is displayed
3. Set an expression in the "Advanced mode configuration" field

   #{currentDocument.type == 'foo' ? 'view' : 'edit'}

4. Observe that the Edit properties and View properties tabs are now displayed
5. Set a vocabulary for each mode
6. Save the widget
7. Edit the widget again
8. Observe that only the Edit properties tab is displayed

Switching between 2 Widget types displays again the 2 tabs but the View properties tab should always be there

GOAL

• We want to always show the view & edit properties when the advanced configuration part is filled
  => will unblock people using the result of a seam bean in there to decide what mode should be shown (related to another support ticket)
  => will also solve the support ticket linked here

TODO

• When advanced mode configuration is not empty, always show both view and edit properties

ACCEPTANCE CRITERIA

• When advanced mode configuration contains only spaces, both properties display is not triggered
• When advanced mode configuration contains text, both view properties and edit properties are available when field loses focus
• When widget is saved, if you reopen the widget's configuration both view and edit properties are still available
• When changing the widget used, if advanced mode configuration is filled both view and edit properties are available