Nightmare Insert Turf Inheretence Issue

### Testmerges

no

### Round ID

_No response_

### Description of the bug

turfs that are from a nightmare insert that are being placed over another turf are inheriting the `baseturfs` var from the original overwritten turf. For example, these turfs have different `baseturfs` values even though they are identical and have not been edited either in game or in the dmi. The only difference is that the one on the right overwrote a jungle tile with `baseturfs = turf/baseturf_bottom` as part of a nightmare insert. Normally this would have zero effect in game but causes issues when using scrapeaways to cause cave collapses as part of a nightmare insert, as turfs affected by this will be replaced by the default plating turf instead of the intended turf.



### What's the difference with what should have happened?

Turfs should have their expected var values instead of ones potentially inherited from whatever they may happen to replace in a nightmare insert

### How do we reproduce this bug?

1.Have a turf with a non-default baseturfs value overwrite a turf that does as part of a nightmare insert
2.Observe the nightmare insert turf having the incorrect value for that var
3.cope, seethe, mald, etc

### Issue Bingo

- [x] Issue could be reproduced at least once
- [ ] Issue happened in a recent (less than 7 days ago) round
- [x] Couldn't find an existing issue about this (https://github.com/cmss13-devs/cmss13/issues)