fix: Add xcall to Frappe's web bundle (backport #15146) (#15152)

Co-authored-by: Omar Younis <oimyounis@gmail.com>

frappe/website/js/website.js

@@ -46,6 +46,20 @@ $.extend(frappe, {
 	hide_message: function() {
 		$('.message-overlay').remove();
 	},
+	xcall: function(method, params) {
+		return new Promise((resolve, reject) => {
+			frappe.call({
+				method: method,
+				args: params,
+				callback: (r) => {
+					resolve(r.message);
+				},
+				error: (r) => {
+					reject(r.message);
+				}
+			});
+		});
+	},
 	call: function(opts) {
 		// opts = {"method": "PYTHON MODULE STRING", "args": {}, "callback": function(r) {}}
 		if (typeof arguments[0]==='string') {