Fixes #25125

**Bug**
Sometimes the scroll position of webviews is reset. The root cause seems to be rapid edits to the markdown preview resulting in the creation of multiple old content iframes

**Fix**
Only maintain two iframes at most. Ensure that these are properly used when updating

* Preserve Webview Scroll Position

Fixes #22995

**Bug**
If you switch away from an editor that users a webview, the scroll position is currently not preserved. This effects our release notes and the markdown preview. The root cause is that the webview is disposed of when the view is hidden.

**Fix**
Add some presisted state to track scrollProgress through the webview. Use this state in the standard html editor and in the release notes.

* Use view state

* Continue prototype memento based approach

* Preserve Webview Scroll Position

Fixes #22995

**Bug**
If you switch away from an editor that users a webview, the scroll position is currently not preserved. This effects our release notes and the markdown preview. The root cause is that the webview is disposed of when the view is hidden.

**Fix**
Add some presisted state to track scrollProgress through the webview. Use this state in the standard html editor and in the release notes.

* Revert changes to ReleaseNotesInput

* Toggle expanded docs, add stickyness to expansion

* New command for moving focus to/from details

* Store user choice in local storage

* Refactoring

* Show prev width for suggest list unless docs expand

* Add keybinding to Read Less button

Fixes #17609

Fix for terminal.foreground not working

Intelli-sense in extensions file