[cmake] define HAVE_{module} flags to check during cmake

cmake/modules/DuneModuleDependencies.cmake

@@ -261,6 +261,8 @@ macro(find_dune_package module)
     endif()
   endif()
   set(DUNE_${module}_FOUND ${${module}_FOUND})
+  dune_module_to_uppercase(_upper_case "${module}")
+  set(HAVE_${_upper_case} "${${module}_FOUND}") # need for example for the python meta data...
 endmacro(find_dune_package module)