Function of GET_CAPABILITIES()

[xiaoyuruan]

I think the GET_CAPABILITIES() should check the Flags returned from Responder and remember the set of capabilities (bits of Flags) that are set both by Requester and Responder. For this session, if caller calls a command that's not in the set of capabilities, then that command function should return error. For example, if Responder did not set CHAL_CAP, then SpdmChallenge() should return error immediately, without sending CHALLEGE to Responder.

[jyao1]

fixed