This reverts commit c1906c79.

* 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 #5745

**Bug**
When zooming in or out, webview contents are not properly sized to fill their parent element

**Fix**
Add a layout method on the webview that manually sets the contents sizes

Two changes:

* Changes the logic from 41467b74 to make the padding customizable. The default 20px padding is preserved, but now preview can customize if they want to use it or not. This allows html preview page background colors to correctly fill the entire frame.

* Remove Writing the `_defaultStyles` to the root of the webview elment. These are only needed inside of the iFrame itself

* Adds command to post a message to an html preview

**Bug**
There is currently no easy way to communicate with an html preview document after the preview has been created.

**Fix**
Adds a command called `vscode.htmlPreview.postMessage` to post a message to a visible html preview. This message will only be posted if the target preview is visible.

Inside the preview, the event is recieved using the standard dom event:

* Remove logging

* proto

Continue proto

* clean up rendering

* Gate prototype

* Fix gating

* Remove public command

* Change setting name

* Added current position indicator

* Reveal center

This extracts the JS content from the webview html into its own file which is loaded using preload instead.