Revert "Folds json_* utilities into json subfolder and adapts includes"

This reverts commit cd039c69c0a92a35889e3c875b8eb53cf07377bb.

unit_tests/util/static_rtree.cpp

@@ -3,6 +3,7 @@
 #include "util/static_rtree.hpp"
 #include "extractor/query_node.hpp"
 #include "extractor/edge_based_node.hpp"
+#include "util/floating_point.hpp"
 #include "util/typedefs.hpp"
 
 #include <boost/functional/hash.hpp>