Improve highlighting structure

- switched to a sparse delta based map
- true lazy-loading to avoid any unneccessary allocations
- fixed windows management api

include/utils/utils.h

@@ -92,6 +92,11 @@ struct Coord {
   bool operator>=(const Coord &other) const { return !(*this < other); }
 };
 
+static inline bool inside(Coord c, Coord pos, Coord size) {
+  return c.row >= pos.row && c.col >= pos.col && c.row - pos.row < size.row &&
+         c.col - pos.col < size.col;
+}
+
 struct Match {
   size_t start;
   size_t end;