Introduce JSON for Modern C++

Summary:
Unify different JSON library usages in MITK to the C++ quasi-standard "JSON for Modern C++"

While it makes sense to stick to certain JSON libraries in a few edge cases like C++ REST SDK and DCMQI, generic handling of JSON in MITK should be done using "JSON for Modern C++".

The following JSON libraries were removed/migrated to "JSON for Modern C++":

• Boost.PropertyTree
• Qt
• Json-cpp (embedded dependency in CppMicroServices module)

Fixes T29208.

Test Plan: Unit tests and manually triggered the execution of JSON code paths with crafted JSON files.

Reviewers: kalali, O1 MITK Reviewer Group I

Reviewed By: kalali, O1 MITK Reviewer Group I

Maniphest Tasks: T29208

Differential Revision: https://phabricator.mitk.org/D664