Migrate transfer valve, assembly holder, and chem grenade to the new attack chain. (#32262)

* Add transfer valve to the new attack chain.

* Apply suggestions from CRUNCH review

Co-authored-by: CRUNCH <143041327+CRUNCH-Borg@users.noreply.github.com>
Signed-off-by: Alan <alfalfascout@users.noreply.github.com>

* Update assembly messages, migrate assembly holder and chem grenade.

* Fix onetankbomb gas analysis.

---------

Signed-off-by: Alan <alfalfascout@users.noreply.github.com>
Co-authored-by: CRUNCH <143041327+CRUNCH-Borg@users.noreply.github.com>

code/game/objects/items/weapons/grenades/chem_grenade.dm

@@ -46,8 +46,6 @@
 	. = ..()
 	display_timer = (stage == READY && !nadeassembly)	//show/hide the timer based on assembly state
 
-
-
 /obj/item/grenade/chem_grenade/proc/get_trigger()
 	if(!nadeassembly) return null
 	for(var/obj/O in list(nadeassembly.a_left, nadeassembly.a_right))
@@ -102,7 +100,7 @@
 		var/turf/bombturf = get_turf(src)
 		var/area/A = get_area(bombturf)
 		if(nadeassembly)
-			nadeassembly.attack_self__legacy__attackchain(user)
+			nadeassembly.activate_self(user)
 			update_icon(UPDATE_ICON_STATE)
 		else if(clown_check(user))
 			// This used to go before the assembly check, but that has absolutely zero to do with priming the damn thing.  You could spam the admins with it.