[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/settings/system/application.fam

@@ -0,0 +1,9 @@
+App(
+    appid="system_settings",
+    name="System",
+    apptype=FlipperAppType.SETTINGS,
+    entry_point="system_settings_app",
+    requires=["gui"],
+    stack_size=1 * 1024,
+    order=70,
+)

applications/settings/system/system_settings.c

@@ -0,0 +1,112 @@
+#include "system_settings.h"
+#include <loader/loader.h>
+#include <lib/toolbox/value_index.h>
+
+const char* const log_level_text[] = {
+    "Default",
+    "None",
+    "Error",
+    "Warning",
+    "Info",
+    "Debug",
+    "Trace",
+};
+
+const uint32_t log_level_value[] = {
+    FuriLogLevelDefault,
+    FuriLogLevelNone,
+    FuriLogLevelError,
+    FuriLogLevelWarn,
+    FuriLogLevelInfo,
+    FuriLogLevelDebug,
+    FuriLogLevelTrace,
+};
+
+static void log_level_changed(VariableItem* item) {
+    // SystemSettings* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+    variable_item_set_current_value_text(item, log_level_text[index]);
+    furi_hal_rtc_set_log_level(log_level_value[index]);
+}
+
+const char* const debug_text[] = {
+    "OFF",
+    "ON",
+};
+
+static void debug_changed(VariableItem* item) {
+    uint8_t index = variable_item_get_current_value_index(item);
+    variable_item_set_current_value_text(item, debug_text[index]);
+    if(index) {
+        furi_hal_rtc_set_flag(FuriHalRtcFlagDebug);
+    } else {
+        furi_hal_rtc_reset_flag(FuriHalRtcFlagDebug);
+    }
+    loader_update_menu();
+}
+
+static uint32_t system_settings_exit(void* context) {
+    UNUSED(context);
+    return VIEW_NONE;
+}
+
+SystemSettings* system_settings_alloc() {
+    SystemSettings* app = malloc(sizeof(SystemSettings));
+
+    // Load settings
+    app->gui = furi_record_open(RECORD_GUI);
+
+    app->view_dispatcher = view_dispatcher_alloc();
+    view_dispatcher_enable_queue(app->view_dispatcher);
+    view_dispatcher_set_event_callback_context(app->view_dispatcher, app);
+
+    view_dispatcher_attach_to_gui(app->view_dispatcher, app->gui, ViewDispatcherTypeFullscreen);
+
+    VariableItem* item;
+    uint8_t value_index;
+    app->var_item_list = variable_item_list_alloc();
+
+    item = variable_item_list_add(
+        app->var_item_list, "Log Level", COUNT_OF(log_level_text), log_level_changed, app);
+    value_index = value_index_uint32(
+        furi_hal_rtc_get_log_level(), log_level_value, COUNT_OF(log_level_text));
+    variable_item_set_current_value_index(item, value_index);
+    variable_item_set_current_value_text(item, log_level_text[value_index]);
+
+    item = variable_item_list_add(
+        app->var_item_list, "Debug", COUNT_OF(debug_text), debug_changed, app);
+    value_index = furi_hal_rtc_is_flag_set(FuriHalRtcFlagDebug) ? 1 : 0;
+    variable_item_set_current_value_index(item, value_index);
+    variable_item_set_current_value_text(item, debug_text[value_index]);
+
+    view_set_previous_callback(
+        variable_item_list_get_view(app->var_item_list), system_settings_exit);
+    view_dispatcher_add_view(
+        app->view_dispatcher,
+        SystemSettingsViewVarItemList,
+        variable_item_list_get_view(app->var_item_list));
+
+    view_dispatcher_switch_to_view(app->view_dispatcher, SystemSettingsViewVarItemList);
+
+    return app;
+}
+
+void system_settings_free(SystemSettings* app) {
+    furi_assert(app);
+    // Variable item list
+    view_dispatcher_remove_view(app->view_dispatcher, SystemSettingsViewVarItemList);
+    variable_item_list_free(app->var_item_list);
+    // View dispatcher
+    view_dispatcher_free(app->view_dispatcher);
+    // Records
+    furi_record_close(RECORD_GUI);
+    free(app);
+}
+
+int32_t system_settings_app(void* p) {
+    UNUSED(p);
+    SystemSettings* app = system_settings_alloc();
+    view_dispatcher_run(app->view_dispatcher);
+    system_settings_free(app);
+    return 0;
+}

applications/settings/system/system_settings.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <furi.h>
+#include <furi_hal.h>
+
+#include <gui/gui.h>
+#include <gui/view_dispatcher.h>
+#include <gui/modules/variable_item_list.h>
+
+typedef struct {
+    Gui* gui;
+    ViewDispatcher* view_dispatcher;
+    VariableItemList* var_item_list;
+} SystemSettings;
+
+typedef enum {
+    SystemSettingsViewVarItemList,
+} SystemSettingsView;