Remove orphaned terms after updating documents

[daun]

• Fix an issue where updating a document won't remove orphaned terms from the index
• The suggested solution is rather crude: delete documents before (re-)indexing them
• There's probably a more elegant solution using upsert, but I can't think of one :)
• Made sure to disable storage revision when making those types of deletions
• Opted for single deletion instead of batching to play nice with transactions and allow rollback
• Fixes Orphaned terms are not removed after updating a document #119

[Toflar]

I would've done exactly the same 😊 I don't think this is a bad approach. But can you target that at main please because this affects 0.8 (aka current stable) as well so we should fix it there. I'll merge it into develop after.

[daun]

@Toflar Rebased on main :) Can't see if the tests are passing. They do locally, anyway.