monaco_editor: lint javascript with typescript compiler

Because typescript is a subset of javascript, running typescript
compiler on javascript files can already report several issues.

https://www.typescriptlang.org/docs/handbook/type-checking-javascript-files.html

bt5/erp5_monaco_editor/SkinTemplateItem/portal_skins/erp5_monaco_editor/monaco-editor.gadget.js.js

@@ -112,6 +112,20 @@
             }
           );
 
+          // Annotations for javascript
+          monaco.languages.typescript.javascriptDefaults.setDiagnosticsOptions({
+            noSemanticValidation: false,
+            noSyntaxValidation: false
+          });
+
+          monaco.languages.typescript.javascriptDefaults.setCompilerOptions({
+            target: monaco.languages.typescript.ScriptTarget.ES6,
+            allowNonTsExtensions: true,
+            checkJs: true,
+            allowJs: true,
+            module: monaco.languages.typescript.ModuleKind.UMD
+          });
+
           // Type mapping for Nexedi libraries
           function addExtraLibrary(script_name, lib_name) {
             return fetch(script_name)