Core: Fixes deprecated calls to jQuery trim (#2328)

Fixes #2327

Co-authored-by: Brighton Balfrey <BBalfrey@fandango.com>

src/core.js

@@ -198,18 +198,25 @@ $.extend( $.fn, {
 	}
 } );
 
+// JQuery trim is deprecated, provide a trim method based on String.prototype.trim
+var trim = function( str ) {
+
+	// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trim#Polyfill
+	return str.replace( /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g, "" );
+};
+
 // Custom selectors
 $.extend( $.expr.pseudos || $.expr[ ":" ], {		// '|| $.expr[ ":" ]' here enables backwards compatibility to jQuery 1.7. Can be removed when dropping jQ 1.7.x support
 
 	// https://jqueryvalidation.org/blank-selector/
 	blank: function( a ) {
-		return !$.trim( "" + $( a ).val() );
+		return !trim( "" + $( a ).val() );
 	},
 
 	// https://jqueryvalidation.org/filled-selector/
 	filled: function( a ) {
 		var val = $( a ).val();
-		return val !== null && !!$.trim( "" + val );
+		return val !== null && !!trim( "" + val );
 	},
 
 	// https://jqueryvalidation.org/unchecked-selector/