Introducing TabView

Introducing TabView
- Adding TabView.
- Synchronous TabView with EditorManager.
- Synchronous TabView with FileController.
- Avoid closure of the last file.
- Persist the last selection of editor.

Possible issue
- If we can manage opened files outside the EditorManager (as its name suggested, it's about editors, not resource). We can detach TabView from EditorManager. I think this can be addressed together with the refactor of supporting multiple types of editors.