cursor: move to a hyprland impl

This moves wlr_cursor to a completely new impl mostly under
CPointerManager

Also adds beginSimple to OpenGL for simple render passes (e.g. cursor)

src/helpers/Vector2D.hpp

@@ -89,6 +89,7 @@ class Vector2D {
     }
 
     double   distance(const Vector2D& other) const;
+    double   distanceSq(const Vector2D& other) const;
     double   size() const;
     Vector2D clamp(const Vector2D& min, const Vector2D& max = Vector2D{-1, -1}) const;