Merge develop into main (#327)

## New features
- Implemented support for app packaging in firmware and `tactility.py`: load `.app` files instead of `.elf` files. Install apps remotely or via `FileBrowser`.
- Ensure headless mode works: all services that require LVGL can deal with the absence of a display
- Service `onStart()` is now allowed to fail (return `bool` result)
- Added and improved various file-related helper functions

## Improvements
- Completely revamped the SystemInfo app UI
- Improved Calculator UI of internal and external variant
- Fix Chat UI and removed the emoji buttons for now
- Fix for toolbar bottom padding issue in all apps

## Fixes
- Fix for allowing recursive locking for certain SPI SD cards
& more

Tactility/Source/service/wifi/WifiMock.cpp

@@ -144,9 +144,10 @@ class WifiService final : public Service {
 
 public:
 
-    void onStart(TT_UNUSED ServiceContext& service) final {
+    bool onStart(TT_UNUSED ServiceContext& service) final {
         tt_check(wifi == nullptr);
         wifi = new Wifi();
+        return true;
     }
 
     void onStop(TT_UNUSED ServiceContext& service) final {