HotColdSolver: Add same-temperature solution narrowing

The hot-cold solver previously was unable to perform narrowing if given
a temperature change of "SAME", leading to less-than-optimal results
when a number of otherwise-possible solutions could be removed from the
possible results by inferring that since they would have yielded a
"COLDER" or "WARMER" temperature change. This commit removes possible
solutions which are absolutely closer or farther from the previous
tested location.

One pre-exisitng test needed to be updated to pass with this change, as
it expected results to be narrowed more slowly than they now are. In
addition, a minimal test case with only two starting locations has been
added to demonstrate this change is working correctly.

runelite-client/src/main/java/net/runelite/client/plugins/cluescrolls/clues/hotcold/HotColdSolver.java

@@ -102,8 +102,10 @@ public class HotColdSolver
 					possibleLocations.removeIf(entry -> isFirstPointCloserRect(lastWorldPoint, worldPoint, entry.getRect()));
 					break;
 				case SAME:
-					// I couldn't figure out a clean implementation for this case
-					// not necessary for quickly determining final location
+					// eliminate spots which are absolutely colder or warmer (as they would not yield a SAME temperature change)
+					possibleLocations.removeIf(entry ->
+						isFirstPointCloserRect(worldPoint, lastWorldPoint, entry.getRect())
+						|| isFirstPointCloserRect(lastWorldPoint, worldPoint, entry.getRect()));
 			}
 		}