assorted proof-related followups

[xgess]

• check the environment for some keybase-specific configs before using the current defaults. this is just nice for development.
• update the identity proof model to trigger the worker on updates as well as creates to handle the case where a user revokes and then re-proves the same identity
• in the case where a user is trying to prove a different mastodon account than the one they're logged into, catch that a little earlier and show a helpful error message.
• 2 little tweaks to the hosted keybase configs that make them easier for keybase to consume
• fix a bug where the very long name of a mastodon instance or a proof provider can overflow in the new proof UI and look bad
• add active proofs to the account panel on the dashboard just like on the profile page
• add an option to post a new status during the identity proof creation flow.

here's what that last change looks like in the UI

and then the post

[Gargron]

This method should have a ? at the end for readability. Could also just name it publish_proof? for simplicity

[Gargron]

accountId is already a string

[Gargron]

Save for the few comments I left, looks fine to me. You should be aware the web UI profile component changed in master (#10337) so you have merge conflicts right now.

[xgess]

thanks @Gargron. conflict fixed. and i like those UI changes on master.