No Longer Store Entire Auth Response

[dshanske]

I'm thinking of adjusting #67, requested by @lostfocus.

There are a few options.

• The simplest is that I would just store the client_id, client_name, client_icon and filter everything else.
• The better option, now that IndieAuth handles this, not Micropub, is to keep a list of clients and just reference that list here.

I had wanted to display the client name for a while. I haven't, but @chrisaldrich mentioning he wanted to made me think I should do this, or at least stop storing unneeded fields.