[Desert Region] Rework canyon variation as same id omts using parameters and z nests

[Procyonae]

Summary

None

Purpose of change

Since this was written there's a cooler way
Ideally I want to improve the canyon mutable enough to replace ravine overmap hardcoding

Describe the solution

Replaces the ided variants with single id maps where the variant is instead controlled by parameter picked nests that are all placed from a single omt to guarantee each vertical column has the same parameter in leui of appropriate scoping #73021

Describe alternatives you've considered

Will probably do the same with the mesa in a follow-up PR
Will hopefully replace hardcoded ravine overmap gen used solely in aftershock exoplanet with an improved canyon mutable in a followup PR
Making the canyon omts linear by z level but that seems overkill rn

Testing

Looks the same in game as far as I can tell, haven't tested migration yet

Additional context