[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/debug/accessor/accessor_event.h

@@ -0,0 +1,19 @@
+#pragma once
+#include <stdint.h>
+
+class AccessorEvent {
+public:
+    // events enum
+    enum class Type : uint8_t {
+        Tick,
+        Back,
+    };
+
+    // payload
+    union {
+        uint32_t menu_index;
+    } payload;
+
+    // event type
+    Type type;
+};