Implemented LaunchId and FileSelection, updated Notes (#281)

- Implemented `LaunchId` to keep track of the apps that are started
- Implemented `FileSelection` app to select existing and/or new files.
- Moved some re-usable file functionality to `tt::file::`
- Renamed `Files` app to `FileBrowser`
- Updated `Notes` app to use new `FileSelection` functionality, and cleaned it up a bit.
- General code cleanliness improvements

Boards/Simulator/Source/Simulator.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "Main.h"
-#include <Tactility/hal/Configuration.h>
 
 namespace simulator {
     /** Set the function pointer of the real app_main() */