This hardcodes the user, and has some other issues, so it is not yet
complete.

We follow mastodon's spec for automatic client registration, available
at both `/api/v1/apps` and a more reasonable `/oauth/client`. This
accepts a JSON POST with the client info and returns JSON with a
`client_id` and a `client_secret`, to be used with `/oauth/authorize`
and `/oauth/token`. It also, seemingly, requires returning an `id`
with unclear purpose.

The `/oauth/token` endpoint doesn't currently return a `me` field.

[CARDS][Forms] Added custom social form theme

[CSS] Replaced/added new classes to be used with forms

Base form theme created, can be extended to create complex blocks to be
called by twig when rendering a specific form.

Refactor feeds and search to use a common query builder

Keep using (deprecated) Guard

Introduce placeholder for abstract upload and thumb modules
Temporarily supress some bugs