enh: refactor askPinCode()

lib/providers/my_wallets.dart

lib/providers/substrate_sdk.dart

lib/providers/v2s_datapod.dart

lib/providers/wallet_options.dart

lib/screens/myWallets/change_pin.dart

lib/screens/myWallets/chest_options.dart

lib/screens/myWallets/choose_chest.dart

lib/screens/myWallets/custom_derivations.dart

lib/screens/myWallets/manage_membership.dart

lib/screens/myWallets/migrate_identity.dart

lib/widgets/bottom_app_bar.dart

lib/widgets/buttons/add_new_derivation_button.dart

lib/widgets/payment_popup.dart