Improve search configuration required fields mapping

In Designer

• tabs
• main menu pages listing
• left menu items search

For all screens above

• When the provider field is not set, the fields
  • schemas
  • search-name

are disabled and a contextual information icon is available.

• Clicking on it displays a dialog saying

  Select provider to map [schemas / search name]

• When a provider is selected / changed,
  • the schemas are filled in / replaced with schemas from:
    • predicates
    • aggregates
  • the search name is filled in / replaced with the page provider name

If changed on modeler side, show a validation warning about missing schemas

For existing configuration, no change is made until someone changes manually the page provider.