Theming: introduce border colors for individual components to override contrastBorder (fixes #26530)

* 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

Refactors TextEditorOptions.fromEditor to a static method instead of an instance method. This method is only called after creation of the options object and currently requires using a weird cast in a few places

- use em dash instead of en dash

fixes #8809
fixes #24014

Closing a tab using middle mouse button on the 'x' causes the tab to the right to also be clsosed (fixes #25529)

themes - get rid of tab.activeWithInactiveEditorGroupForeground and inactiveWithInactiveEditorGroupForeground

From: https://github.com/Microsoft/TypeScript/issues/15352

TS 2.3.1 introduced a breaking change by [switching to covariant types for callbacks](https://github.com/Microsoft/TypeScript/wiki/Breaking-Changes#covariance-in-callback-parameters). This change tries to fix these compiler errors in the workbench codebase