New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/geometry/diamond_box.cpp

@@ -0,0 +1,10 @@
+#include "geometry/diamond_box.hpp"
+
+namespace m2
+{
+DiamondBox::DiamondBox(std::vector<PointD> const & points)
+{
+  for (auto const & p : points)
+    Add(p);
+}
+}  // namespace m2