Make chem dispenser reagent search better (#72358)

Improving the chem dispenser reagent search by using a List.

This is my first Pull Request for tgstation. I would like to know how to
add Test for this change.

Make the Input more fun to Use by letting the player search in a reagent
list. Helps for typing complicated chemical names.

code/modules/reagents/chemistry/holder.dm

@@ -1911,7 +1911,7 @@
 			ui_reaction_id = text2path(params["id"])
 			return TRUE
 		if("search_reagents")
-			var/input_reagent = (input("Enter the name of any reagent", "Input") as text|null)
+			var/input_reagent = tgui_input_list(usr, "Select reagent", "Reagent", GLOB.chemical_name_list)
 			input_reagent = get_reagent_type_from_product_string(input_reagent) //from string to type
 			var/datum/reagent/reagent = find_reagent_object_from_type(input_reagent)
 			if(!reagent)