Refactoring on `utils.cc' and adjacents

Completely removed the `utils.cc' by moving residual functions into
sub-classes of `utils/'

test/unit/unit_test.cc

@@ -23,12 +23,13 @@
 #include <iterator>
 
 #include "common/colors.h"
-#include "src/utils.h"
 #include "src/utils/regex.h"
 #include "utils/msc_string.h"
 
+
 using modsecurity::utils::String;
 
+
 namespace modsecurity_test {