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

Tactility/Source/app/timedatesettings/TimeDateSettings.cpp

@@ -88,7 +88,7 @@ public:
         }
     }
 
-    void onResult(AppContext& app, Result result, std::unique_ptr<Bundle> bundle) override {
+    void onResult(AppContext& app, TT_UNUSED LaunchId launchId, Result result, std::unique_ptr<Bundle> bundle) override {
         if (result == Result::Ok && bundle != nullptr) {
             auto name = timezone::getResultName(*bundle);
             auto code = timezone::getResultCode(*bundle);