Widgets: Rename Text widget's legacy mode to non-visual mode, restore boolean filter prop, and improve compatibility for widget_text filters applied in Custom HTML widget.

Props westonruter, obenland, timmydcrawford for testing.
Amends [41050].
See #35243, #40951, #40907.
Fixes #41394.

Built from https://develop.svn.wordpress.org/trunk@41132


git-svn-id: http://core.svn.wordpress.org/trunk@40972 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/widgets/text-widgets.js

@@ -368,7 +368,7 @@ wp.textWidgets = ( function( $ ) {
 		}
 
 		// Bypass using TinyMCE when widget is in legacy mode.
-		if ( widgetForm.find( '.legacy' ).length > 0 ) {
+		if ( ! widgetForm.find( '.visual' ).val() ) {
 			return;
 		}
 
@@ -429,7 +429,7 @@ wp.textWidgets = ( function( $ ) {
 		}
 
 		// Bypass using TinyMCE when widget is in legacy mode.
-		if ( widgetForm.find( '.legacy' ).length > 0 ) {
+		if ( ! widgetForm.find( '.visual' ).val() ) {
 			return;
 		}