nfc: On-device tag generator (#1319)

* nfc: Add tag generator base
* nfc: Fix BCC generation
* nfc: Add MFUL EV1 generators
* nfc: Fix typos in generator
* nfc: Add NTAG21x generators
* nfc: More const
* nfc: Add NTAG I2C generators
* nfc: Add field names to generator initializers
* nfc: Move generators to add manually scene
* nfc: Revise tag generator UX
* nfc: Revert add manually menu item name
* nfc: Remove unused scene start submenu index

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

applications/nfc/nfc.c

@@ -84,6 +84,9 @@ Nfc* nfc_alloc() {
     view_dispatcher_add_view(
         nfc->view_dispatcher, NfcViewDictAttack, dict_attack_get_view(nfc->dict_attack));
 
+    // Generator
+    nfc->generator = NULL;
+
     return nfc;
 }