* Use new fetcher implementation for post/comment
* rewrite person fetch to use new fetcher
* rewrite community to use new fetcher
* rename new_fetcher to dereference_object_id
* make ObjectId a newtype
* handle deletion in new fetcher
* rewrite apub object search to be generic
* move upsert() method out of ApubObject trait
* simplify ObjectId::new (and fix clippy)
* Use URL type in most outstanding struct fields
This fixes all known remaining cases where url fields are stored as
plain strings, with the exception of form fields where empty strings
are used as sentinels (see `diesel_option_overwrite_to_url`).
Tested for regressions in the federated docker setup attempting to
exercise all changed fields, including through apub federation.
Fixes#1385
* Add migration to fix blank-string post.url values to be null
This also then fixes#602
* Address review feedback
- Fixed some unwraps and err message formatting
- Bumped the `url` library to 2.2.1 to fix a bug with serde error
messages
- Add unit tests for the two diesel option override functions
- Fix migration teardown by adding a no-op
* Rename lemmy_db_queries::Url to lemmy_db_queries::DbUrl
* fix compile error
* box PostOrComment variants
