As an editor I want to see constraints violations on Form or Sense statements right after saving them in order to see mistakes in the data and fix them.

Problem:
Right now statements on the Form and Sense level are not checked for constraints violations when saving a statement.

Screenshots/mockups:

BDD
GIVEN a an edit on a statement on a Form or Sense
AND the resulting statement violates a constraint
WHEN saving the edit
THEN the violation should be checked and indicated via the little constraint violation icon

Acceptance criteria:

• statements on Forms and Senses are checked for constraint violations and indicate them to the user in the same way as constraint violations on Item or Lexeme-level statements when saving the statement
• no page reload is necessary

Technical notes:
When a statement is saved and the gadget makes the action=wbcheckconstraints&claims=… request, the API returns constraint violations (that part actually works), but the results don’t become visible on the page. The gadget’s DOM selectors probably need to be massaged a bit.