Move tapir-nima into tapir

[kciesielski]

Helidon 4.0.0 has been released, so we can move the Nima 4 interpreter from https://github.com/softwaremill/tapir-loom into tapir.
One important consideration here is that tapir-nima requires JDK21 to run its tests, while we'd like to keep other servers to run tests on JDK 11. This task would then need changes in CI workflow to accommodate for such a requirement.