[REF] qweb: improve t-on generated code

and deduplicate logic between directive t-on applied on a node and on a
component

src/utils.ts

@@ -58,7 +58,7 @@ export function escape(str: string | number | undefined): string {
   if (typeof str === "number") {
     return String(str);
   }
-  const p = document.createElement('p');
+  const p = document.createElement("p");
   p.textContent = str;
   return p.innerHTML;
 }