RS - Remove orphan attachments from db after a record is updated

[issammani]

We got a user report that Firefox on iOS is taking a lot of space ( also confirmed this is happening on Android too ). We managed to narrow it down to the quicksuggest-amp.sql db in remote settings being 1GB+ in some cases. See Slack thread for more context.

This happens because whenever we update a record's attachment or tombstone a record we never clean up the orphan attachments. This should happen for all collections. I am assuming this manifested itself in quicksuggest-amp because we update it frequently.

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[issammani]

@bendk I made the tests specific to suggest just for context but let me know if it's better to just have dummy names instead.

[bendk]

This seems good to me, but I think someone on the DISCO team should review.

@ncloudioj what do you think?

[ncloudioj]

Thanks for the tag, Ben! Will defer to @gruberb for r? as he has more context on the RS client than i do. Bastian, can you take a look at this? TIA

[gruberb]

Looks correct to me!