fixes #70695

Fixes #66561

Fixes #65920

fixes #65920

fixes #66617

fixes #66226

fixes #65012

Many `Promise.resolve(null)` should actually be `Promise.resolve(void 0)`. In other cases, we were missing a null return annotation.

Fixes a common type error

These methods return an IEditor as a result but even if the opening fails or the editor was not opened as active.

The fix is to check for the result of the open call and only return the editor if the editor was opened actually.

This restores the behaviour we had before GRID.

fixes #64767

This reverts commit a8e6a919.

#53526

fixes #62346