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/app/wificonnect/View.cpp

@@ -55,6 +55,7 @@ static void onConnect(TT_UNUSED lv_event_t* event) {
     service::wifi::settings::WifiApSettings settings;
     strcpy((char*)settings.password, password);
     strcpy((char*)settings.ssid, ssid);
+    settings.channel = 0;
     settings.auto_connect = TT_WIFI_AUTO_CONNECT; // No UI yet, so use global setting:w
 
     auto* bindings = &wifi->getBindings();