Bools and returns super-pr (#53221)

Replaces like 70-80% of 0 and such, as a side effect cleaned up a bunch of returns
Edit: Most left out ones are in mecha which should be done in mecha refactor already
Oh my look how clean it is

Co-authored-by: TiviPlus <TiviPlus>
Co-authored-by: Couls <coul422@gmail.com>

code/modules/procedural_mapping/mapGenerator.dm

@@ -89,17 +89,16 @@
 //Checks for and Rejects bad region coordinates
 //Returns 1/0
 /datum/map_generator/proc/checkRegion(turf/Start, turf/End)
-	. = 1
-
 	if(!Start || !End)
-		return 0 //Just bail
+		return FALSE //Just bail
 
 	if(Start.x > world.maxx || End.x > world.maxx)
-		. = 0
+		return FALSE
 	if(Start.y > world.maxy || End.y > world.maxy)
-		. = 0
+		return FALSE
 	if(Start.z > world.maxz || End.z > world.maxz)
-		. = 0
+		return FALSE
+	return TRUE
 
 
 //Requests the mapGeneratorModule(s) to (re)generate
@@ -153,10 +152,10 @@
 		return
 
 	var/endInput = input(usr,"End turf of Map (X;Y;Z)", "Map Gen Settings", "[world.maxx];[world.maxy];[mob ? mob.z : 1]") as text|null
-	
+
 	if (isnull(endInput))
 		return
-	
+
 	//maxx maxy and current z so that if you fuck up, you only fuck up one entire z level instead of the entire universe
 	if(!startInput || !endInput)
 		to_chat(src, "Missing Input")