handle player death

[h3ndrik]

If the player dies, they stay attached to the helicopter. That means a window opens telling you that you've died, but you don't respawn but stay in the helicopter. And sometimes i respawned, but jumped back into the helicopter as soon as i returned and got closer to the old helicopter.

(Try: flying into lava or fire)

other mods using mobkit detach players on death, disconnect or server shutdown:

• https://github.com/ElCeejo/mob_core/blob/3ed7338317e1b0ef00cd6eefd4c694377c12e475/mount.lua#L64
• https://github.com/runsy/petz/blob/8fee22f2a6442fed326bac63c3abaf6cb72a13bf/petz/misc/mount.lua#L12

Also i had a few crashes when mob_core was installed on my testing singleplayer world.

[wsor4035]

@h3ndrik would you mind rebasing this pr? thanks