runelite-api: Optimize getClickbox

- Use the pre-calculated center/extreme xyz fields for the aabb
 - use modelToCanvas and reduce indirection
 - Use a specialized union that only does axis-aligned rectangles
     instead of the Area class
 - Use a specialized intersection that only does convex polygons, again
     to avoid Area

runelite-api/pom.xml

@@ -57,5 +57,11 @@
 			<version>4.12</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-simple</artifactId>
+			<version>1.7.12</version>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 </project>