Cleanup: More accurate output parameter type for CTVerifier

The CTVerifier interface took a CTVerifyResult* as an output parameter.
This change replaces the output parameter with
SignedCertificateTimestampAndStatusList*, which is the only output all
implementations of the CTVerifier interface could provide.

Other fields in the CTVerifyResult struct are filled in by other entities
and CTVerifier implementations have no ability to fill them in (or any
need to access them at all).
So it is cleaner, and more conservative, to only provide the SCT List
to be filled to the CTVerifier.

BUG=653825

Review-Url: https://codereview.chromium.org/2400183002
Cr-Commit-Position: refs/heads/master@{#424146}
16 files changed