New LF-RFID app (#534)

* Hal lfrfid: add read timer pulse and period config fns
* New debug application for lfrfid subsystem
* New lfrfid: app, fix naming
* App lfrfid: assets
* Container view module
* App ibutton: remove unused header
* App lfrfid scenes
* App notification, add yield to blocking operations, add speaker volume control
* App lfrfid: reading key scene
* Assets: placeholder icon
* App lfrfid: reworked container view module
* App lfrfid: new scenes
* App lfrfid: write scene
* App lfrfid: write hid
* App lfrfid: emulate scene
* App lfrfid: save name scene
* App lfrfid: add missing file

lib/app-scened-template/file-worker.cpp

@@ -0,0 +1,60 @@
+#include "file-worker.h"
+
+FileWorker::FileWorker()
+    : fs_api{"sdcard"}
+    , sd_ex_api{"sdcard-ex"} {
+    string_init(error_string);
+}
+
+FileWorker::~FileWorker() {
+    string_clear(error_string);
+}
+
+bool FileWorker::open(const char* filename, FS_AccessMode access_mode, FS_OpenMode open_mode) {
+    bool result = fs_api.get()->file.open(&file, filename, access_mode, open_mode);
+
+    if(!result) {
+        show_error_message("Cannot open\nfile");
+        close();
+        return false;
+    }
+
+    return check_common_errors();
+}
+
+bool FileWorker::close() {
+    fs_api.get()->file.close(&file);
+
+    return check_common_errors();
+}
+
+bool FileWorker::mkdir(const char* dirname) {
+    FS_Error fs_result = fs_api.get()->common.mkdir(dirname);
+
+    if(fs_result != FSE_OK && fs_result != FSE_EXIST) {
+        show_error_message("Cannot create\nfolder");
+        return false;
+    };
+
+    return check_common_errors();
+}
+
+bool FileWorker::remove(const char* filename) {
+    FS_Error fs_result = fs_api.get()->common.remove(filename);
+    if(fs_result != FSE_OK && fs_result != FSE_NOT_EXIST) {
+        show_error_message("Cannot remove\nold file");
+        return false;
+    };
+
+    return check_common_errors();
+}
+
+bool FileWorker::check_common_errors() {
+    sd_ex_api.get()->check_error(sd_ex_api.get()->context);
+    return true;
+}
+
+void FileWorker::show_error_message(const char* error_text) {
+    string_set_str(error_string, error_text);
+    sd_ex_api.get()->show_error(sd_ex_api.get()->context, string_get_cstr(error_string));
+}