Port Request: "Dash" Spell Effect

[RobbieNeko]

Is your feature request related to a problem? Please describe.

We, as of yet, do not have any target teleport / movement effects in the spellcode other than the janky work-around of SWAP_POS flag. This is a fairly big limitation on the spells we can implement.

Describe the solution you'd like

Port the spell effect "Dash" from DDA, originally found in this DDA PR.

Additional context

I'm somewhat surprised this wasn't already ported, especially given we've tried to port bits of it before.