Adds a new INHALE reagent transfer method and applies it to smoking and smoke inhalation. Nitrous oxide (the reagent version) inhalation causes brain damage. (#87306)

## About The Pull Request

Adds the ``INHALE`` transfer method. Smoking and smoke exposure now uses
this method.

Makes a few sensible inhalation effects for current behaviours.

Adds a unit test amongst the rest of the exposure method tests.

Nitrous oxide does brain damage on inhalation based on volume inhaled.

## Why It's Good For The Game

Smoke and smoking being based on ingestion rather than inhaling was
always weird to me. It'd be nice to have a specific method for smoking
instead of a method shared by drinking. Many of our smokables make sense
as indigestibles, obviously, but maybe we'd like a chem you can ONLY
smoke.

~~Also, I walked out of a job interview and up the street to see a guy
throwing his empty nitrous canisters around and yelling at passerbys, so
shout out to that fucking guy with this PR.~~

## Changelog
🆑
code: Introduces a INHALE method for reagent transfer. Cigarettes and
smoke reactions use this new method.
balance: Nitrous oxide now brain damage if you inhale it. So don't do
that.
/🆑

---------

Co-authored-by: SyncIt21 <110812394+SyncIt21@users.noreply.github.com>
Co-authored-by: Ghom <42542238+Ghommie@users.noreply.github.com>

code/game/objects/effects/effect_system/fluid_spread/effects_smoke.dm

@@ -391,7 +391,7 @@
 
 	var/fraction = (seconds_per_tick SECONDS) / initial(lifetime)
 	reagents.copy_to(smoker, reagents.total_volume, fraction)
-	reagents.expose(smoker, INGEST, fraction)
+	reagents.expose(smoker, INHALE, fraction)
 	return TRUE
 
 /// Helper to quickly create a cloud of reagent smoke