HLKZ quality of life features

[YaLTeR]

• [ ] Automatic demo stop-record on teleport to start position / respawn
• [ ] Automatic demo stop-rename on pressing the finish button, configurable to continue recording for up to n seconds after the button press (or up to the next start position / respawn (configurable to only with PB?)
• [x] Strafing HUD (think CGAZ HUD in Defrag) - this one was requested in BXT and could be cool to have
• [ ] Client-side timer (I wonder how much it'll differ from the serverside one)

[execut4ble]

• [x] Ability to hide other players. Probably fine if they still make sounds but are invisible, if it's impossible to remove that.
• [ ] Add ability to create clientside checkpoints that work like custom BXT triggers. It should be able to detect when you start the timer and once you pass through the checkpoint it will show how much you're behind/ahead your previous attempts. Would also be cool if you could export/save checkpoints and times into a file like you can with splits.
• [ ] HLKZ/Gamemode configs. I use slightly different binds on HLKZ than when I'm playing regular AG so it would be nice if I could point a certain config I want to use when playing HLKZ and then I don't have to rebind stuff all the time.

[execut4ble]

Invisible players have been implemented serverside in the HL KreedZ plugin.