Old mvdsv-only PR1 extensions not available

[meag]

These were removed from pr1_cmds.c in fccc8a4 (https://github.com/deurk/mvdsv/blob/00fb82c92b6640a042c642586e32d7944851bd43/src/pr_cmds.c#L3239-L3263)

Example was given of OZTF, which can no longer run on mvdsv as it relies on these functions being available.

Is it just the policy that old mods are not supported now, or would it be safe to add these back in (along with a cvar to perform same function as the also-removed sv_ktpro_mode)?