[json] Stop serializing cw_source into default json representation of an entity
Related to #15538288
===================
Changelog history
===================
.. include:: 3.23.rst
.. include:: 3.22.rst
.. include:: 3.21.rst
.. include:: 3.20.rst
.. include:: 3.19.rst
.. include:: 3.18.rst
.. include:: 3.17.rst
.. include:: 3.16.rst
.. include:: 3.15.rst
.. include:: 3.14.rst