Trigger bloodfledge coffin healing on-demand

Prevents quirk processing from running by default for Bloodsucker Fledgling. Processing is started and stopped by being inside a coffin when it is opened or closed. Messages have been added for all start and stop interactions.

The following changes are made for Bloodfledges:
- Added quirk processing triggers to coffins
- Added coffin check for robotic mob biotypes
- Added return for non-coffin locations to quirk processing
- Added feedback messages for open, close, synthetic, fully healed, and starving
- Removed robotic biotype check from processing
- Removed obsolete brute and burn damage adjustments
- Stop processing if fully healed
- Stop processing if below nutrition requirement

modular_splurt/code/game/objects/structures/crates_lockers/crates.dm

@@ -0,0 +1,56 @@
+/obj/structure/closet/crate/coffin/examine(mob/user)
+	. = ..()
+
+	// Define carbon user
+	var/mob/living/carbon/coffin_examinee
+
+	// Check if carbon user exists
+	if(!istype(coffin_examinee))
+		return
+
+	// Check for bloodfledge
+	if(HAS_TRAIT(coffin_examinee, TRAIT_BLOODFLEDGE))
+		. += span_cult("As a Bloodsucker Fledgling; You can use coffins like this one to heal your wounds and escape from death.")
+
+/obj/structure/closet/crate/coffin/after_close(mob/living/coffin_toucher)
+	. = ..()
+
+	// Iterate over carbon mobs inside
+	for(var/mob/living/carbon/coffin_user in contents)
+		// Check for bloodfledge
+		if(HAS_TRAIT(coffin_user, TRAIT_BLOODFLEDGE))
+			// Check for synthetic
+			if(coffin_user.mob_biotypes && (coffin_user.mob_biotypes & MOB_ROBOTIC))
+				// Warn user and continue
+				to_chat(coffin_user, span_warning("Your components don't respond to [src]'s sanguine connection! Regeneration will not be possible."))
+				continue
+
+			// User is not synthetic
+
+			// Define quirk entry
+			var/datum/quirk/bloodfledge/quirk_target = locate() in coffin_user.roundstart_quirks
+
+			// Start processing
+			START_PROCESSING(SSquirks, quirk_target)
+
+			// Alert user
+			to_chat(coffin_user, span_nicegreen("[src] empowers your connection to the other-world, allowing your body to mend."))
+
+/obj/structure/closet/crate/coffin/after_open(mob/living/coffin_toucher)
+	. = ..()
+
+	// Define turf
+	var/turf/coffin_turf = get_turf(src)
+
+	// Iterate over carbon mobs inside
+	for(var/mob/living/carbon/coffin_user in coffin_turf.contents)
+		// Check for bloodfledge
+		if(HAS_TRAIT(coffin_user, TRAIT_BLOODFLEDGE))
+			// Define quirk entry
+			var/datum/quirk/bloodfledge/quirk_target = locate() in coffin_user.roundstart_quirks
+
+			// Stop processing
+			STOP_PROCESSING(SSquirks, quirk_target)
+
+			// Alert user
+			to_chat(coffin_user, span_notice("[src] is no longer empowering you."))