Add layout and functionality for 2d broken link checker

[kishore03109]

@hanpuliu-charles todo fill this up ya

Problem

Closes [insert issue #]
This pr implements the 2 level broken link checker interface, moving individual errors on a page into a modal, that overlays over main broken link checker page, which now provides a summary listing the page and number of errors on it in a table.

Solution

Implemented the design here.

Breaking Changes

• Yes - this PR contains breaking changes
  • Details ...
• No - this PR is backwards compatible with ALL of the following feature flags in this doc

Features:

• Improves usability of the broken link checker function, making it less cluttered(No longer listing all errors on a single page.)

Improvements:

• Splitting of tables into 2 levels(Site level table shown at first, listing each page with error and error count, and page level table which is in a modal shown when user clicks the 'Review Page' link.)
• Now attempts to classify the different types of links into hyperlinks(both relative and absolute), email
• Using the above, display some hints to the user on suggested ways to rectify the errors(It's quite limited at the moment)

Before & After Screenshots

BEFORE:

AFTER:

Tests

• Unit tests (using npm run tests)
• e2e tests (comment on this PR with the text !run e2e)
• Smoke tests
  Not too sure about this. No new test added.

[kishore03109]

I cannot approve since it is a pr i created.
This is ok from my end, all the comments here are just nits. once the nits are resolved, proceed to approve this pr and reember to squah and merge into dev

also moving forward, when creating commits, use commitcitizen for your commits ya

sorry for the delay in review, good work on your first pr!

[kishore03109]

ya seems like this is unchanged

[hanpuliu-charles]

Addressed all nits, proceeding to approve this PR