Revert "fix: many null checks fixed (#2059)" (#2065)

This reverts commit 63ea9a2.

Author: LukasDeco

sdk/src/constants/txConstants.ts

@@ -4,5 +4,3 @@ export const NOT_CONFIRMED_ERROR_CODE = -1001;
 export const FUEL_RESET_LOG_ACCOUNT = new PublicKey(
 	'FuE1gqp2fzw2sDNLrbZqKsqpphJcoSW6HPaSJjGd4RZ4'
 );
-
-export const DEFAULT_COMMITMENT_LEVEL = 'confirmed';