[FL-2627] Flipper applications: SDK, build and debug system (#1387)

* Added support for running applications from SD card (FAPs - Flipper Application Packages)
* Added plugin_dist target for fbt to build FAPs
* All apps of type FlipperAppType.EXTERNAL and FlipperAppType.PLUGIN are built as FAPs by default
* Updated VSCode configuration for new fbt features - re-deploy stock configuration to use them
* Added debugging support for FAPs with fbt debug & VSCode
* Added public firmware API with automated versioning

Co-authored-by: hedger <hedger@users.noreply.github.com>
Co-authored-by: SG <who.just.the.doctor@gmail.com>
Co-authored-by: あく <alleteam@gmail.com>

applications/services/bt/bt_settings.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "bt_settings_filename.h"
+
+#include <stdint.h>
+#include <stdbool.h>
+
+typedef struct {
+    bool enabled;
+} BtSettings;
+
+bool bt_settings_load(BtSettings* bt_settings);
+
+bool bt_settings_save(BtSettings* bt_settings);