* 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

fixes #10179

fixes #8308

#7961

fixes #7969