[dv, test_vectors] Integrate AES test vectors into existing NIST vector testing package

The [test_vectors](https://github.com/lowRISC/opentitan/tree/master/hw/dv/sv/test_vectors) area currently cater to SHA256, HMAC, SHAKE and KMAC vectors from NIST. For AES, a separate solution is being developed in PR #6981. Ideally, it should integrate a flow for all AES modes / length as well.

Start in the hw/dv/sv/test_vectors area and review how the existing NIST SHA256, HMAC, SHAKE, and KMAC vectors are handled. Compare that flow with the AES solution in PR #6981, then define how all AES modes and lengths should integrate. Done means AES vectors use the existing NIST vector-testing package flow.

Written by the indexing model from the issue text.