Rename fd_reality_tear back to fd_fatigue (fix tilesets, migration)

[RenechCDDA]

Summary

None

Purpose of change

fd_fatigue was renamed to fd_reality_tear in #72708, but we do not have any migration handling for fields. This causes existing instances of the field to throw errors on load and disappear (as a valid field cannot be found for them).

Additionally, because the ID has changed the tilesets no longer have an entry for them. This causes them to revert to their looks_like of smoke. The actual graphics are pretty cool, so I'd like to keep them.

Describe the solution

Revert this naming change.

Describe alternatives you've considered

Implement migration handling and figure out the tileset incantations to move its sprites around?

Testing

Load this save without the patch, notice field errors and no tears in reality exist on load:
FIELDS NAME-trimmed.tar.gz

(Without saving) Load after patch, notice fields exist and look like they should on all tiles builds with in-repo tilesets

Additional context

This causes the reverse problem for builds created between April 4th and the merging of this PR, in that fd_reality_tear generated in saves between them will disappear. This is not ideal, but the issue will not occur for anyone moving from 0.H--->a hypothetical future 0.I, which is desirable.

[github-actions]

Auto-requesting reviews from non-collaborators: @LyleSY @Standing-Storm

[I-am-Erk]

I don't have strong opinions on this, and a revert is probably the right change for now given the knock on effects, but I think we need a mechanic to change these. It's relatively minor thing that fd_fatigue doesn't make sense as a name, but it's a problem when we have no mechanic to change an ID for any reason.

Also though I really dislike fd_fatigue, it's just one of those things that adds another element of nuisance to content addition/editing for no reason.