[Forms] Let Angular force required rows

Pass along ng-required values such that Angular may
handle tracking of form validity based on the presence
of required fields. WTD-530.

platform/forms/src/MCTControl.js

@@ -50,6 +50,9 @@ define(
                     // Enabled/disabled state
                     ngDisabled: "=",
 
+                    // Whether or not input is required
+                    ngRequired: "=",
+
                     // Pattern (for input fields)
                     ngPattern: "=",