Add checks to prevent De-AMP loops

[ShivanKaul]

Resolves brave/brave-browser#22610

1. Set a header called "X-Brave-De-AMP" that we check for before De-AMPing.
2. If canonical/target URL is the same as the current pending URL, don't De-AMP.

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, npm run lint, 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/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

1. https://shivankaul.com/brave/de-amp/test-redirect-loop-1.html and https://shivankaul.com/brave/de-amp/test-redirect-loop-2.html are 2 AMP pages that point to each other. Visiting one should not cause a redirect loop.
2. https://www.airlive.net/new-footage-shows-an-ukrainian-mig-29-taking-off-from-mykolaiv-seconds-before-the-runway-is-shelled-by-the-russians/ should not cause constant reloading of the page.

[bridiver]

this needs to start from the original amp page to properly replicate the issue as mentioned in DM and on the issue

[bridiver]

we'll do a follow-up to address tests, etc.. when you're back from pto