refactor: Clio Config (#1593)

Add constraint + parse json into Config
Second part of refactoring Clio Config; First PR found
[here](https://github.com/XRPLF/clio/pull/1544)

Steps that are left to implement:
- Replacing all the places where we fetch config values (by using
config.valueOr/MaybeValue) to instead get it from Config Definition
- Generate markdown file using Clio Config Description

tests/unit/util/newconfig/ValueViewTests.cpp

@@ -20,6 +20,7 @@
 #include "util/newconfig/ConfigDefinition.hpp"
 #include "util/newconfig/ConfigValue.hpp"
 #include "util/newconfig/FakeConfigData.hpp"
+#include "util/newconfig/Types.hpp"
 #include "util/newconfig/ValueView.hpp"
 
 #include <gtest/gtest.h>