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/wifiapsettings/WifiApSettings.cpp

@@ -112,7 +112,7 @@ class WifiApSettings : public App {
         }
     }
 
-    void onResult(TT_UNUSED AppContext& appContext, TT_UNUSED Result result, std::unique_ptr<Bundle> bundle) override {
+    void onResult(TT_UNUSED AppContext& appContext, TT_UNUSED LaunchId launchId, TT_UNUSED Result result, std::unique_ptr<Bundle> bundle) override {
         if (result == Result::Ok && bundle != nullptr) {
             auto index = alertdialog::getResultIndex(*bundle);
             if (index == 0) { // Yes