Feature request: support Typesense as Full-Text Search backend

Hello @eikek

I'm planning to self-host Docspell for personal use. I already have a small [Typesense](https://typesense.org/) cluster, so I would rather use that instead of setting up a dedicated Solr for Full-Text search.

I'm an experienced Java developer, and while I never used Scala, I would like to give it a try and implement the fts interfaces.
If I manage, would you review a PR? I guess It would require adding a new depedency.

For reference:
- https://typesense.org/docs/
- https://github.com/typesense/typesense-java
- https://docspell.org/docs/configure/fulltext-search/

Anyway, Thank you.