Fix verbose email addresses being passed to mail adapters

Summary:
Fixes T5233.

  - The mail adapter API currently expects plain addresses (like `a@b.com`) in `addTos()`, and some adapters can not accept fancy verbose addresses (like `"name" <a@b.com>`).
  - When we try to send error email, we pass the entire "From" header into the API. This is incorrect.
  - Since it would be nice to make this just work in the future, fix it inside the API.
  - Specifically, this is reached with: send email -> generates error -> we try to send you an email back -> we send it to your "From" -> some mailers choke on the fancy name if you have one.

Test Plan: Processed an errorneous email with a fancy "From", got a response error.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5233

Differential Revision: https://secure.phabricator.com/D10232