Server record (`NETMSGTYPE_SV_RECORD`) is not always stored in demos

[Robyt3]

The NETMSGTYPE_SV_RECORD message is only stored in demos if the recording was started when connecting or if the server record is changed while the demo is recorded.

The client could store the last received NETMSGTYPE_SV_RECORD and always add it at the beginning when starting a new demo recording, to ensure that demos always contain this information. Though the server record would still potentially be incorrect when skipping in the demo, same as #4545 for teams.

[heinrich5991]

Should be put into the snapshot instead, I guess.