[FL-2970] Untangle NFC_APP_FOLDER from nfc_device (#2124)

* Untangle NFC_APP_FOLDER from nfc_device
* Make the folder an internal part of the nfc device struct
* Move the NFC folder definition to the nfc allocator
* Move the NFC folder definition to the allocator in the nfc magic FAP
* Replace furi_string_printf with furi_string_set for folder allocation and handle the cases when folder has no slashes
* Build and allocation fixes

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

applications/main/nfc/nfc.c

@@ -46,6 +46,7 @@ Nfc* nfc_alloc() {
 
     // Nfc device
     nfc->dev = nfc_device_alloc();
+    furi_string_set(nfc->dev->folder, NFC_APP_FOLDER);
 
     // Open GUI record
     nfc->gui = furi_record_open(RECORD_GUI);

applications/main/nfc/nfc_i.h

@@ -44,6 +44,7 @@
 ARRAY_DEF(MfClassicUserKeys, char*, M_PTR_OPLIST);
 
 #define NFC_TEXT_STORE_SIZE 128
+#define NFC_APP_FOLDER ANY_PATH("nfc")
 
 typedef enum {
     NfcRpcStateIdle,