Setup Certificate Search

[king-alexander]

🗣 Description

This pull request makes several changes to setup the sslmate Certificate Search API as our method to monitor and query Certificate Transparency logs.

💭 Motivation and context

The current service we use to monitor Certificate Transparency logs is too unreliable. This change provides more stability at the scale we operate.

🧪 Testing

Over a few dry runs of load_certs.py, I have processed approximately 200 domains.

In addition, all unit and system tests passed (Python 3.10.4, pytest-7.2.0).

✅ Pre-approval checklist

• [x] This PR has an informative and human-readable title.
• [x] Changes are limited to a single goal - eschew scope creep!
• [x] All future TODOs are captured in issues, which are referenced in code comments.
• [x] All relevant type-of-change labels have been added.
• [x] I have read the CONTRIBUTING document.
• [x] These code changes follow cisagov code standards.
• [x] All new and existing tests pass.

✅ Pre-merge checklist

• [x] Revert dependencies to default branches.
• [x] Finalize version.

✅ Post-merge checklist

• [ ] Add a tag or create a release.