Tweaking flooring procs to allow for multiple flooring layers.

[MistakeNot4892]

Description of changes

• Adds handling to _flooring for multiple floor types on the same turf.
• Changes wild grass to be dirt, grass, wild grass and adds a snowy grass type (dirt, grass, snow).

I would like some input on this one as it is blowing out init time on Shaded Hills 250% (almost a full minute) and there are some odd instances of completely black turfs.

Why and what will this PR improve

Allows for things like snow accumulation without ChangeTurf() or overriding the lower turf types.

Authorship

Myself.

Changelog

Nothing player-facing currently.

[MistakeNot4892]

Init time is still very bloated, up to 30 seconds from 20, but I fixed the icon issues.

[out-of-phaze]

as discussed on discord i think we'll need to do the 3-var approach where we cache the topmost flooring value, and the intermediary layers are in a list var. this will probably result in it accessing being faster than it was before lol