Milestone 8

Last week I worked on completing the prototypes. However, due to a weird problem with Solr and a minor health problem, I couldn't complete them as planned so I'm still working on them. They should be finished in the first half of the next week.
Afterwards, I will evaluate their performance and go on to work on a final version of the module, combining the two approaches.

Still active:

• #491288: Start work on prototypes
• #517366: Compare prototype results and discuss best option(s)
• #517356: Update upcoming milestones/tasks to more concrete ones
• #517368: Work on getting this module to a usable state