Apply Trustable Software Framework (TSF) to nlohmann_json

S-CORE is planning to use the [Trustable Software Framework](https://projects.eclipse.org/projects/technology.tsf) in the scope of qualification of open-source components. The idea is to use nlohmann_json as a pilot component for the TSF. The TSF in S-CORE is described in https://eclipse-score.github.io/process_description/main/trustable/index.html

Repository with nlohmann_json fork and TSF artifacts: https://github.com/eclipse-score/nlohmann_json

The progress is tracked in the [Baselibs FT](https://github.com/orgs/eclipse-score/discussions/categories/base-libs-ft) and the [Process Community](https://github.com/orgs/eclipse-score/discussions/categories/sw-dev-process-community)