Nfc: add field testing (#1027)

* Nfc: add field cli command
* Nfc: add field test in debug menu
* Nfc: warning message for field tests
* Format sources

applications/nfc/scenes/nfc_scene_field.c

@@ -0,0 +1,34 @@
+#include "../nfc_i.h"
+
+void nfc_scene_field_on_enter(void* context) {
+    Nfc* nfc = (Nfc*)context;
+
+    furi_hal_nfc_field_on();
+
+    Popup* popup = nfc->popup;
+    popup_set_header(
+        popup,
+        "Field is on\nDon't leave device\nin this mode for too long.",
+        64,
+        11,
+        AlignCenter,
+        AlignTop);
+    view_dispatcher_switch_to_view(nfc->view_dispatcher, NfcViewPopup);
+
+    notification_internal_message(nfc->notifications, &sequence_set_blue_255);
+}
+
+bool nfc_scene_field_on_event(void* context, SceneManagerEvent event) {
+    return false;
+}
+
+void nfc_scene_field_on_exit(void* context) {
+    Nfc* nfc = (Nfc*)context;
+
+    notification_internal_message(nfc->notifications, &sequence_reset_blue);
+
+    Popup* popup = nfc->popup;
+    popup_reset(popup);
+
+    furi_hal_nfc_field_off();
+}