fixes #55886

- avoid public modifier
- use Disposable where applicable
- fix some event handler leaks
- clean up some TODO@ben

This reverts commit 27256832 which turns out did not break the import of vs/nls

This reverts commit 7de696a2.

Seems to have broken loading vs/nls in at least one case in insiders

Don't use this import form in places where it is not needed. This prevents us from correctly detecting duplicate imports

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