Move customSpreadFactors from config to some datapack file

[Povstalec]

It would be incredibly useful if other mods could override the spread of some specific Structures by simply using datapacks.

Having this be controlled by the config removes the ability of other mod devs to fix any issues their structures are experiencing thanks to Sparse Structures changing their intended generation position, making them (to a degree) incompatible with Sparse Structures.

(To give an example, Stargate Journey has a certain set of structures which rely on always generating on some specified coordinates, which means the presence of Sparse Structures causes trouble by preventing them from generating where they are supposed to generate)

[MaxenceDC]

That's a very interesting and valid point, I'm not sure yet as to how I could implement this, but I will definitely look at it further.

[Povstalec]

Lovely, thank you for your time.