Move PHUIErrorView to PHUIInfoView

Summary: Since this element isn't strictly about errors, re-label as info view instead.

Test Plan: Grepped for all callsites, tested UIExamples and a few other random pages.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: hach-que, Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11867