Certificate Transparency: Code for unpacking EV cert hashes whitelist

Re-submission of https://codereview.chromium.org/462543002/ (note that the Fingerprint256 changes have been broken off to a separate change).

Note for the build cop: Please attempt to contact me if there's a need to roll back.

BUG=339128

Review URL: https://codereview.chromium.org/547603002

Cr-Commit-Position: refs/heads/master@{#301642}
17 files changed