[FIX] *: move OwlError to common

This commit moves OwlError to its own file in the new common folder
such that it is no longer associated with the runtime.

tests/components/error_handling.test.ts

@@ -20,7 +20,7 @@ import {
   useLogLifecycle,
   nextAppError,
 } from "../helpers";
-import { OwlError } from "../../src/runtime/error_handling";
+import { OwlError } from "../../src/common/owl_error";
 
 let fixture: HTMLElement;