Add diesel_async, get rid of blocking function (#2510)

Add diesel_async, get rid of blocking function (#2510)

* Moving settings to Database.

- Moves many settings into the database. Fixes #2285
- Adds a local_site and instance table. Fixes #2365 . Fixes #2368
- Separates SQL update an insert forms, to avoid runtime errors.
- Adds TypedBuilder to all the SQL forms, instead of default.

* Fix weird clippy issue.

* Removing extra lines.

* Some fixes from suggestions.

* Fixing apub tests.

* Using instance creation helper function.

* Move forms to their own line.

* Trying to fix local_site_data, still broken.

* Testing out async

* Testing out async 2

* Fixing federation tests.

* Trying to fix check features 1.

* Starting on adding diesel async. 1/4th done.

* Added async to views and schema.

* Adding some more async

* Compiling now.

* Added diesel async. Fixes #2465

* Running clippy --fix

* Trying to fix cargo test on drone.

* Trying new muslrust.

* Trying a custom dns

* Trying a custom dns 2

* Trying a custom dns 3

* Trying a custom dns 4

* Trying a custom dns 5

* Trying a custom dns 6

* Trying a custom dns 7

* Addressing PR comments.

* Adding check_apub to all verify functions.

* Reverting back drone.

* Fixing merge

* Fix docker images.

* Adding missing discussion_languages.

* Trying to fix federation tests.

* Fix site setup user creation.

* Fix clippy

* Fix clippy 2

* Test api faster

* Try to fix 1

* Try to fix 2

* What are these lines about

* Trying to fix 3

* Moving federation test back to top.

* Remove logging cat.