Refactor app access (#205)

- Use `tt::app::` functions to start/stop apps and get current app(context) instead of using loader everywhere
- Removed `tt_service_loader.*` from TactilityC
- Created `tt_app_stop()` for TactilityC
- Bumped version to 0.3.0 to prepare for upcoming release

TactilityC/Include/tt_app.h

@@ -29,6 +29,9 @@ bool tt_app_has_result(AppHandle handle);
  */
 void tt_app_start(const char* appId);
 
+/** Stop the currently running app */
+void tt_app_stop();
+
 /**
  * Start an app by id and bundle.
  * @param[in] appId the app manifest id

TactilityC/Include/tt_service_loader.h

@@ -1,33 +0,0 @@
-#pragma once
-
-#include "tt_app.h"
-#include "tt_bundle.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
- * Start an application providing a manifest id and an optional bundle.
- * Execution is always deferred.
- * This function generally returns immediately unless the scheduler is blocked.
- * @param[in] id application manifest id
- * @param[in] bundle an allocated bundle (or NULL) of which the memory ownership is handed over to this function
- */
-void tt_service_loader_start_app(const char* id, BundleHandle _Nullable bundle);
-
-/**
- * Stop the currently active app.
- * Execution is always deferred.
- * This function generally returns immediately unless the scheduler is blocked.
- */
-void tt_service_loader_stop_app();
-
-/**
- * Get the context handle of the app that is currently shown on the screen.
- */
-AppHandle tt_service_loader_get_current_app();
-
-#ifdef __cplusplus
-}
-#endif