[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/gui/view_stack.h

@@ -0,0 +1,61 @@
+/**
+ * @file view_stack.h
+ * GUI: ViewStack API
+ *
+ * ViewStack accumulates several Views in one stack.
+ * Draw callbacks are called sequenctially starting from
+ * first added. Input callbacks are called in reverse order.
+ * Consumed input is not passed on underlying layers.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include "view.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** ViewStack, anonymous type. */
+typedef struct ViewStack ViewStack;
+
+/** Allocate and init ViewStack
+ *
+ * @return      ViewStack instance
+ */
+ViewStack* view_stack_alloc(void);
+
+/** Free ViewStack instance
+ *
+ * @param       view_stack  instance
+ */
+void view_stack_free(ViewStack* view_stack);
+
+/** Get View of ViewStack.
+ * Should this View to any view manager such as
+ * ViewDispatcher or ViewHolder.
+ *
+ * @param       view_stack  instance
+ */
+View* view_stack_get_view(ViewStack* view_stack);
+
+/** Add View to ViewStack.
+ * Adds View on top of ViewStack.
+ *
+ * @param       view_stack  instance
+ * @view        view        view to add
+ */
+void view_stack_add_view(ViewStack* view_stack, View* view);
+
+/** Remove any View in ViewStack.
+ * If no View to remove found - ignore.
+ *
+ * @param       view_stack  instance
+ * @view        view        view to remove
+ */
+void view_stack_remove_view(ViewStack* view_stack, View* view);
+
+#ifdef __cplusplus
+}
+#endif