[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/rpc/rpc_app.h

@@ -0,0 +1,32 @@
+#pragma once
+#include "rpc.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+    RpcAppEventSessionClose,
+    RpcAppEventAppExit,
+    RpcAppEventLoadFile,
+    RpcAppEventButtonPress,
+    RpcAppEventButtonRelease,
+} RpcAppSystemEvent;
+
+typedef void (*RpcAppSystemCallback)(RpcAppSystemEvent event, void* context);
+
+typedef struct RpcAppSystem RpcAppSystem;
+
+void rpc_system_app_set_callback(RpcAppSystem* rpc_app, RpcAppSystemCallback callback, void* ctx);
+
+void rpc_system_app_send_started(RpcAppSystem* rpc_app);
+
+void rpc_system_app_send_exited(RpcAppSystem* rpc_app);
+
+const char* rpc_system_app_get_data(RpcAppSystem* rpc_app);
+
+void rpc_system_app_confirm(RpcAppSystem* rpc_app, RpcAppSystemEvent event, bool result);
+
+#ifdef __cplusplus
+}
+#endif