[FL-935] Queue-based SD app cycle. File select widget. (#388)

* SD App: more specific sd api
* Gui: view dispatcher fix api documentation
* Gui: view holder thingy
* SD App: do not sleep when working with sd card bus
* SD App: queue-based lifecycle
* Assets: sd-card assets
* SD App: init file select api

Co-authored-by: あく <alleteam@gmail.com>

lib/common-api/sd-card-api.h

@@ -0,0 +1,22 @@
+#pragma once
+#include <furi.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct SdApp SdApp;
+
+typedef struct {
+    SdApp* context;
+    bool (*file_select)(
+        SdApp* context,
+        const char* path,
+        const char* extension,
+        char* result,
+        uint8_t result_size);
+} SdCard_Api;
+
+#ifdef __cplusplus
+}
+#endif