Part of #74250

- Extend `Disposable` in classes where it makes sense
- Use `DisposableStore` for lists of disposables
- Make `combinedDisposable` take arguments instead of an array (so that you can't pass in an array and then modify the array after the fact)

Fixes #74191

Instead of using a base64 encoded data uri to display images, use the fileService to read Buffer, convert this to a Blob, and display the blob

Expose vscode.openIssueReporter command that allows passing an extensionId to open the reporter with