Enhance support for federation extension

[m-mohr]

In the EOEPCA+ project, we made an evaluation of the federation-related functionality available through the openEO Web Editor.
We made significant improvements through #230

The following issues are left, but are all upstream issues and have a low priority due to the missing implementation in backends at this point:

• federation:missing can't be accessed through the corresponding functions for the following endpoints:
  • GET /jobs/:id/logs
  • GET /services/:id/logs
• federation:backends can't be accessed through the corresponding functions for the following endpoints:
  • GET /udf_runtimes per version
  • GET /services/{id}

Related issue for the upstream issues in Vue Components: Open-EO/openeo-vue-components#97