Enable SCT enforcement

[fmarier]

This makes Brave follow the same Certificate Transparency policy as Chrome for TLS certificates.

It also excludes Brave hostnames which are involved with browser updates in order to ensure that updates always work even if the certificate transparency code breaks in the future.

Resolves brave/brave-browser#22482

Security review: https://github.com/brave/security/issues/1245

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally:
  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run lint, npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/TLS-Policy

Test Plan:

Follow these steps on desktop and Android:

1. Open https://no-sct.badssl.com/ in Brave.
2. Confirm that there's a TLS error page (NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED).
3. Open https://sct-exempted.bravesoftware.com in Chrome.
4. Confirm that there's a TLS error page (NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED).
5. Open https://sct-exempted.bravesoftware.com in Brave.
6. Confirm that the page loads fine.

[fmarier]

Note: the test page is not yet live (https://github.com/brave/devops/issues/9497), but the approach is ready for review. I will wait for that test page to be live before merging.

Also, CI is not passing yet, but from what I can see it's not caused by changes in this PR. I will investigate more once CI is more stable. It sounds like many PRs are affected at the moment.