Index attachments with search_api and Apache Tika

I'm moving this issue to the latest branch (8.0.x-dev), because I think this would be a super-useful feature!

8.0.x-dev integrates tightly with Search API → , so I forecast that adding support for Search API attachments → (which supports Apache Tika, among others) should be mostly straightforward.

#3308913-4: Support for Attachments → (for Search API OpenSearch ✨ Support for Attachments Closed: cannot reproduce ) suggests it might already work... I'll start by testing elasticsearch_connector, search_api_attachments, and Apache Tika, and if I can get it working, I will write documentation on how to set it up; or if I can't, then I will update this issue to plan out what it will take to get it working.

(I am doing a big review of open issues across all branches for 🌱 [Meta] Roadmap for a stable release with security coverage Active : thank you for your patience with me)