Refactor account delta check test #1104
Description
The rpc_server_rejects_proven_transactions_with_invalid_commitment test checks the account delta's commitment provided in the transaction against a computed one in the RPC component, to ensure that it wasn't changed. The test builds a ProvenTransaction "handmade", by using the new method.
To ease the testing here, and in some other places where we ProvenTransactions, this issue (0xMiden/protocol#1628) aims to add a prove_dummy method in the provers, so we can avoid having to prove for real which would hurt the performance of tests.