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/Private/app/wifimanage/State.h

@@ -30,8 +30,12 @@ public:
 
     void updateApRecords();
 
-    const std::vector<service::wifi::ApRecord>& lockApRecords() const;
-    void unlockApRecords() const;
+    template <std::invocable<const std::vector<service::wifi::ApRecord>&> Func>
+    void withApRecords(Func&& onApRecords) const {
+        mutex.withLock([&]() {
+            std::invoke(std::forward<Func>(onApRecords), apRecords);
+        });
+    }
 
     void setConnectSsid(const std::string& ssid);
     std::string getConnectSsid() const;