build: move map & rng logic to their own libraries

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I1802469f3baff4576f61accfb5a197d86a6a6964

libs/map/utils.c

@@ -0,0 +1,13 @@
+#include "utils.h"
+
+int clamp(int value, int min, int max) {
+  if (value < min)
+    return min;
+  if (value > max)
+    return max;
+  return value;
+}
+
+int in_bounds(int x, int y, int width, int height) {
+  return x >= 0 && x < width && y >= 0 && y < height;
+}