Added cl_team_sounds_volume

[chinese-soup]

Hello.

Motivation: This is useful against play_team and play_close "spamming" [quotation marks because each sound gets replaced by the previous one] both of which send PlaySound UserMsg to players on your team and players on your team that are close to you, respectively. While this can be useful for normal DM for e.g. notifying about dropping weapons to your teammates with a specific sound, etc. it can get annoying on HLKreedz and other gamemodes, therefore this PR introduces a cvar to toggle being bombarded with sounds.

Video: https://user-images.githubusercontent.com/5108747/157968525-dd9c54cf-2300-4e3d-80ee-63c6722c3a59.mp4

What this disables: Just play_team and play_close, the usermsg isn't used anywhere else in the ServerDLL for any other sounds. Proof: user msg reg https://github.com/fireblizzard/agmod/blob/9dfa990c95ee37a7d5370d5f834220f80da4dd11/src/dlls/player.cpp#L279 (and then the msg isn't used anywhere else) AgClient::Play call: https://github.com/fireblizzard/agmod/blob/9dfa990c95ee37a7d5370d5f834220f80da4dd11/src/dlls/agclient.cpp#L237 AgClient::Play code: https://github.com/fireblizzard/agmod/blob/989b156b6583b5c1ce6d815284714efa595c7b9c/dlls/agclient.cpp#L779

[chinese-soup]

now that i think of it, this could instead be a volume cvar too, huh

[YaLTeR]

now that i think of it, this could instead be a volume cvar too, huh

Yeah I think that's a good idea

[chinese-soup]

Yeah I think that's a good idea

Yeah, sorry, will do. Originally I thought it'd be a good idea to have the cvars named in-line with already existing ones: https://github.com/YaLTeR/OpenAG/pull/150

[YaLTeR]

Thanks