Improve support for the Federation Extension

[m-mohr]

In the EOEPCA+ project, we made an evaluation of the federation-related functionality available through the openEO Vue Components.
The Federation Extension can be found here: https://github.com/Open-EO/openeo-api/blob/draft/extensions/federation/README.md

The following issues have been identified:

• 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}

Some parts are generally not covered by the Vue Components (job listing, file listing, service listing, validation results) so these are naturally also not implementing the Federation extension.

[m-mohr]

Implemented as part of v2.20.0