Added 16x16 region file support

[MarvelcoCode]

Description

Region files now use 16×16 chunk regions for new worlds while preserving 32×32 for existing saves.

Changes

Previous Behavior

All worlds used 32×32 chunk region files, which broke saved DLC's

Root Cause

No distinction was made between new and existing worlds when choosing the region file format.

New Behavior

New worlds use 16×16 region files, Old worlds automatically fall back to 32×32 if those files are already present. (this also alows us to use newer tut worlds like tu19 tu20 etc and porting worlds from newer versions)

Fix Implementation

In _getRegionFile, before constructing the 16×16 file path, we check if a 32×32 region file already exists and use it instead.

I tested new worlds, old worlds and DLC's creation, saving and reloading

[MarvelcoCode]

dont merge i discovered a bug

[MarvelcoCode]

i will open another pr that is better

[MarvelcoCode]

#1169