This PR moves the entire project to Typescript. Due to the ~1000 ignores this will lead to a messy codebase for a while, but the churn is worth it – all of those ignore comments are places that were never type-safe previously.
closes#1282
* fix: Server error if attempting to load an unknown attachment
* fix: Migration should cascade delete to document attachments
* fix: Delete S3 attachments along with documents