Make Alby Account Optional

[rolznz]

Fixes #484

This makes Alby Hub usable without an account by replacing the forced auth with an optional connect flow, and a way to disconnect from the settings. Alby Account specific cards and onboarding steps are removed from the UI.

TODOs:

• suggestions API is not usable without an Alby Account
• first channel flow redirects to channels/incoming - added illustration, but no "first channel" copy - I think this is ok for now?
• new connect account page needs a design iteration - moved to new issue: Improve Connect Alby Account page #642
• review copy around connecting/disconnecting account
• fix version check - does not show out of date, just the current version, and there is no link to update.
• satoshi nakamoto name is weird but is a subtle way to motivate users to connect their account for customization
• automatic re-auth if you already had an Alby Account with an expired refresh token
• update to use new Alby info endpoint https://getalby.com/api/internal/info

[reneaaron]

Nice work! 💯

Most of the things work like a charm, however when I try to re-connect my account I seem to be stuck in a redirect loop: (might be related to my dev setup?)