* Use fixed access tokens instead of fetching an access token with the OAuth flow. This assumes
access tokens won't expire, which seems to be true for the default app-level access token, unless
you manually regenerate it. Fixes the OAuth flow not working on Baraag for some reason.
* Eliminate the MastodonApiClient class. Just inline it in the extractor instead.
Downstream users will need to update their configs to set the `pawoo_access_token` and
`baraag_access_token` config options.
