add kill immunity for /practice

[teini94]

example:in /practice useing Dyn Cam and using /tc to teleport often results in ur teleporting very unprecise into a kill tile and then u respawn + ur view resets. so u have to go all the way over again with ur view quite annoying

so I would add kill immunity atleast for 1-2frames, so u should be able to use /lasttp and still change ur postion with /tc

[BlaiZephyr]

this has been discussed in multiple issues and Pullrequests before - see #2221 #7691 #3024

[Robyt3]

Duplicate of #2232.