#31372

More manual conversion of index based for loops to for-of loops

Code like:

```
private readonly _onDidEncounterLanguage: Emitter<LanguageId> = new Emitter<LanguageId>();
```

Does not need to repeat the `Emitter<LanguageId>` type annotation

We compile using the alwaysStrict flag so these directives are not needed

This part removes most `use strict` directives that are right after the file header

fixes #57789

There are many places in the code that do `import Event, { ...} from '.../event'`.