[Suggestion] Make Dynamic Time/Velocity Separate Configurations

[CustomStats]

The shavit_replay_timedifference convar enables both the dynamic time and dynamic velocity differences in the HUD, but it would be awesome to have these as separate convars so server owners can decide if they want this specific new feature (dynamic velocity), rather than having it be all or nothing.

[rtldg]

I'll add a !hud setting for velocity-difference because I forgot to do that, but I'm not sure a cvar is worth adding for it.

[rtldg]

I added a hud option for velocity different and the shavit_hud2_default cvar can be used to enable/disable it by default 87e64c8