For #82592

Fixes #81847

this function is no longer being used

This matchs the naming of a few other services we have

Fixes #81788

Fixes #81434

- Make image preview a ui exension

- Add logic so that `asWebviewUri` supports preserving the scheme of the requested resource. This is important as we know where to load the resource from

This fixes an issue where webviews for custom editors did not have any associated extension information, which caused them try reading `file:` uri resources instead of remote uri resources

Fixes #79424

This file depends on dom api so it should live in browser instead of common

#78168

For #77132

This change attempts to do the following:

- Encapsult most of the logic for handling the webviews used for webview editors into a new WebviewEditorOverlay class
- Greatly simplify WebviewEditorInput and make it take a webview when it is created
- Move the webview creation logic up into the webviewEditorService instead of having it be inside the webviewEditor class itself

This aim of these changes is to make it possible to re-use more of the webview logic for custom editors

Fixes #77132

Add support for loading webviews from and endpoint that looks like:

```
https://{{uuid}}.contoso.com/path/to/some/commit/index.html
```

This lets us serve each webview from a seperate origin