Cleanup and improvements (#194)

- Lots of changes for migrating C code to C++
- Improved `Lockable` in several ways like adding `withLock()` (+ tests)
- Improved `Semaphore` a bit for improved readability, and also added some tests
- Upgrade Linux machine in GitHub Actions so that we can compile with a newer GCC
- Simplification of WiFi connection
- Updated funding options
- (and more)

Tactility/Source/Tactility.h

@@ -7,18 +7,22 @@
 
 namespace tt {
 
+namespace app::launcher { extern const app::AppManifest manifest; }
+
 /** @brief The configuration for the operating system
  * It contains the hardware configuration, apps and services
  */
 struct Configuration {
     /** HAL configuration (drivers) */
-    const hal::Configuration* hardware;
+    const hal::Configuration* hardware = nullptr;
     /** List of user applications */
     const std::vector<const app::AppManifest*> apps = {};
     /** List of user services */
     const std::vector<const service::ServiceManifest*> services = {};
     /** Optional app to start automatically after the splash screen. */
-    const char* _Nullable autoStartAppId = nullptr;
+    const std::string launcherAppId = app::launcher::manifest.id;
+    /** Optional app to start automatically after the splash screen. */
+    const std::string autoStartAppId = {};
 };
 
 /**