Requester state transitions

[steven-bellock]

Currently if the Requester receives an error response SPDM_ERROR_CODE_REQUEST_RESYNCH from the Responder libspdm automatically changes the connection state to LIBSPDM_CONNECTION_STATE_NOT_STARTED

libspdm/library/spdm_requester_lib/libspdm_req_handle_error_response.c

Lines 99 to 102 in 57ac200

	if (error_code == SPDM_ERROR_CODE_REQUEST_RESYNCH) {
	spdm_context->connection_info.connection_state =
	LIBSPDM_CONNECTION_STATE_NOT_STARTED;
	}

This violates a library pattern where state changes need to be initiated by the integrator. So in this specific case we could have it so that

1. The integrator would see that a resynch is requested and the libspdm connection state remains unchanged.
2. It is up to the integrator to call libspdm_init_connection.

There may be use cases (TBD) where the integrator doesn't want libspdm to automatically change state.

[jyao1]

3/21/2022 - we agree this is an issue. Need give a full list of improper state change.