Oauth updates

[gwbischof]

There are a good amount of updates to the lemmy v0.20.0 API. This PR fixes the ones that are required to run with v0.20.0 and to support OAuth/SSO. There may be additional api changes also.

LemmyNet/lemmy@0.19.6...main
LemmyNet/lemmy-js-client@0.19.6...0.20.0-alpha.18

Some v0.20.0 api changes that I see so far:

• SSO support
• remove local_site.enableNsfw
• remove local_site.enableDownvotes
• remove local_user.defaultSortType
• remove local_user.showScores
• add local_user.defaultCommentSortType
• add local_user.defaultPostSortType

I am following this blog post from @privacyguard to implement the SSO
https://privacyportal.org/blog/sign-in-with-privacy-portal-tutorial

[hjiangsu]

Thanks for starting work on the v0.20.x changes! I just made a quick comment for how to approach any newly added values in the API. Let me know if you need further guidance on adding/removing fields.

[hjiangsu]

I just committed a couple of things:

• Updated this PR to resolve conflicts with the master branch (this was due to me updating some stuff with the repo)
• Removed the .swp files that were included in the PR (I believe they were maybe added in by mistake?)

Aside from that, I believe this looks good to me!