Split the link checker workflow into HTTP and Relative link checker (#16104)

* link-checker.md fixes

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* copilot comments fixes

* bash indent fixes

* explicit check for relative links is added

* reduce token load

* minor change

* Initial plan

* Fix link checker anchor validation

Co-authored-by: azat-msft <290065318+azat-msft@users.noreply.github.com>

* skipping domain on 429, fixing trailing parens in https links

* token-wise cautious prompt for broken anchors

* removed testing http links

* separate http link checker added

* changed names of checkers

* compiled old link checker removed

* resolving copilot comments

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Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: azat-msft <290065318+azat-msft@users.noreply.github.com>

Author: 3 people