Implement unit testing (#30)

- Create `test` and `tactility-core-tests` subprojects
- Created tests for `thread.c`
- Fixed issue with thread cleanup (see what I did there? :P)
- Removed functions from `thread.h` that did not exist anymore
- Updated `ideas.md`

docs/ideas.md

@@ -1,13 +1,9 @@
 # TODOs
 - Update `view_port` to use `ViewPort` as handle externally and `ViewPortData` internally
 - Replace FreeRTOS semaphore from `Loader` with internal `Mutex`
-- Create unit tests for `tactility-core` and `tactility` (PC-only for now)
+- Create more unit tests for `tactility-core` and `tactility` (PC-only for now)
 - Have a way to deinit LVGL drivers that are created from `HardwareConfig`
-- Thread is broken: `tt_thread_join()` always hangs because `tt_thread_cleanup_tcb_event()`
-is not automatically called. This is normally done by a hook in `FreeRTOSConfig.h`
-but that seems to not work with ESP32. I should investigate task cleanup hooks further.
 - Set DPI in sdkconfig for Waveshare display
-- Try to drive Yellow Board backlight with PWM to reduce backlight strength
 - Show a warning screen if firmware encryption or secure boot are off when saving WiFi credentials.
 - Show a warning screen when a user plugs in the SD card on a device that only supports mounting at boot.
 - Try out Waveshare S3 120MHz mode for PSRAM (see "enabling 120M PSRAM is necessary" in [docs](https://www.waveshare.com/wiki/ESP32-S3-Touch-LCD-4.3#Other_Notes))
@@ -20,7 +16,6 @@ but that seems to not work with ESP32. I should investigate task cleanup hooks f
 - If present, use LED to show boot status
 
 # App Improvement Ideas
-- Make a Settings app to show all the apps that have a "settings" app type (and hide those in desktop)
 - Sort desktop apps by name.
 - Light/dark mode selection in Display settings app.