Merge develop into main (#313)

- Add app path get() functions to `TactilityC`
- Improved `Dispatcher` and `DispatcherThread`
- Improved `PubSub` (type safety)
- Created test for `DispatcherThread` and `PubSub`
- Save properties files on app exit (various apps) by posting it to the main dispatcher (fixes UI hanging briefly on app exit)
- Fixed bug with `SystemSettings` being read from the wrong file path.
- `loadPropertiesFile()` now uses `file::readLines()` instead of doing that manually
- Increased timer task stack size (required due to issues when reading a properties file for the very first time)
- General cleanup
- Created `EstimatedPower` driver that uses an ADC pin to measure voltage and estimate the battery charge that is left.
- Cleanup of T-Deck board (updated to new style)

Tests/TactilityCore/PubSubTest.cpp

@@ -0,0 +1,35 @@
+#include "doctest.h"
+#include <Tactility/TactilityCore.h>
+#include <Tactility/PubSub.h>
+
+using namespace tt;
+
+TEST_CASE("PubSub publishing with no subscriptions should not crash") {
+    PubSub<int> pubsub;
+    pubsub.publish(1);
+}
+
+TEST_CASE("PubSub subscription receives published data") {
+    PubSub<int> pubsub;
+    int value = 0;
+
+    auto subscription = pubsub.subscribe([&value](auto newValue) {
+        value = newValue;
+    });
+    pubsub.publish(1);
+
+    CHECK_EQ(value, 1);
+}
+
+TEST_CASE("PubSub unsubscribed subscription does not receive published data") {
+    PubSub<int> pubsub;
+    int value = 0;
+
+    auto subscription = pubsub.subscribe([&value](auto newValue) {
+        value = newValue;
+    });
+    pubsub.unsubscribe(subscription);
+    pubsub.publish(1);
+
+    CHECK_EQ(value, 0);
+}