Stop exposing raw "accountID" values directly in the web UI

Summary:
Ref T13493. The "AuthAccountView" UI element currently exposes raw account ID values, but I'm trying to make these many-to-one.

This isn't terribly useful as-is, so get rid of it. This element could use a design refresh in general.

Test Plan: Viewed the UI element in "External Accounts".

Maniphest Tasks: T13493

Differential Revision: https://secure.phabricator.com/D21010