Enhance missile collision in SpawnLightning

[obligaron]

Fixes #4384

Notes:

• After investigating this is the same problem as #2837.
• Extract fix from #2831 in new function (first commit).
• Used the same logic for SpawnLightning
• SpawnLightning wasn't converted to MoveMissileAndCheckMissileCol, cause it doesn't call CheckMissileCol.
• The same problem could occur in other places UpdateMissilePos is used (for example rhino). This is not addressed with this pr.

[obligaron]

@AJenbo could you take a look? If this is merged, I could use the new missile helpers introduced in #4632 (separate pr, cause i also want to change scrollrt.cpp). 🙂 Else I would get a merge conflict. 😉