Deserializes a result set and verifies the signature bytes. Returns false
if bRequireFullOnlineVerify is set but Steam is running in Offline mode.
Otherwise returns true and then delivers error codes via GetResultStatus.
The bRESERVED_MUST_BE_FALSE flag is reserved for future use and should not
be set to true by your game at this time.
DeserializeResult has a potential soft-failure mode where the handle status
is set to k_EResultExpired. GetResultItems() still succeeds in this mode.
The "expired" result could indicate that the data may be out of date - not
just due to timed expiration (one hour), but also because one of the items
in the result set may have been traded or consumed since the result set was
generated. You could compare the timestamp from GetResultTimestamp() to
ISteamUtils::GetServerRealTime() to determine how old the data is. You could
simply ignore the "expired" result code and continue as normal, or you
could challenge the player with expired data to send an updated result set.
