Validator that can parse and validate SignedCsrPayload Cbor object.
The SignedCsrPayload is generated by
OEMCrypto_GetDeviceSignedCsrPayload() and will be put into prov4 CSR
request during factory uploading.
Test: opk_ta_p40
Bug: 300304834
Change-Id: Ib569dc22fe76dbaa98657e96aa4c93a272bbcd1b