Add a type in the natvis template for detail::json_default_base

[sakuntalle]

With version 3.12.0 the underlying type for a nlohmann::json object has become nlohmann::json_abi_diag_v3_12_0::detail::json_default_base and this type does not have a Type definition in the corresponding natvis template and generated natvis file.

This PR updates the Natvis jinja template to add all the types derived from json_default_base. Also the template is rendered to produce the nlohmann_json.natvis

fixes #4972

• [x] The changes are described in detail, both the what and why.
• [x] If applicable, an existing issue is referenced.
• [ ] The Code coverage remained at 100%. A test case for every new line of code.
• [ ] If applicable, the documentation is updated.
• [ ] The source code is amalgamated by running make amalgamate.

Read the Contribution Guidelines for detailed information.

[coveralls]

coverage: 99.191%. remained the same when pulling 78ede22f92352ef545ba099b01e3a2558dcdaa6b on sakuntalle:develop into a6a92c19bf1be371655e477d09f3d8455ca6fb89 on nlohmann:develop.

[github-actions[bot]]

This pull request has been marked as stale because it has had no activity for 30 days. While we won’t close it automatically, we encourage you to update or comment if it is still relevant. Keeping pull requests active and up-to-date helps us review and merge changes more efficiently. Thank you for your contributions!