This change adds the initial implementation of the new API server in Kotlin,
replacing the old API written in Python. The implementation uses Quarkus,
RESTEasy, and Hibernate to implement the new API endpoints.

The reason for replacing the old API server is unifying the build and
deployment toolchains, reducing the number of technologies necessary to
work with OpenDC. Furthermore, we envision bundling the entire OpenDC
project into a single distributions, allowing users to launch their own
deployment trivially.

This change adds additional endpoints to the REST API to access the
project relations, the portfolios and topologies that belong to a
project.

This change adds an API endpoint for simulation jobs which allows API
consumers to manage simulation jobs without needing direct database
access that is currently needed for the web runner.

This change updates the API to use Flask Restful instead of our own
in-house REST library. This change reduces the maintenance effort and
allows us to drastically simplify the API implementation needed for the
OpenDC v2 API.