Add nlohmann_json to bazel registry and update dependency in baselibs module

Currently, baselibs module depends on the upstream `nlohmann_json` module from BCR: https://github.com/eclipse-score/baselibs/blob/v0.2.2/MODULE.bazel#L129

The Trustable Software Framework requires that all source code is mirrored to a controlled environment:
https://codethinklabs.gitlab.io/trustable/trustable/doorstop/TA.html#ta-supply_chain
And therefore, the baselibs module should use the approved version and not from BCR.

This task includes:

- [x] Renaming `inc_nlohmann_json` to `nlohmann_json`. It is agreed in https://github.com/orgs/eclipse-score/discussions/434?sort=new#discussioncomment-15473384
Example how to do it: https://github.com/eclipse-score/.eclipsefdn/pull/88
PR: https://github.com/eclipse-score/.eclipsefdn/pull/127
- [ ] Adding the `nlohmann_json` to the [S-CORE bazel registry](https://github.com/eclipse-score/bazel_registry). The module name should be prefixed with `score_`. I.e. `score_nlohmann_json`. Enable automatic version update if needed.
- [ ] Changing the dependency in https://github.com/eclipse-score/baselibs/blob/main/MODULE.bazel to point to the S-CORE bazel registry.