DOJO(admin): Create the page to manage flagged exercises

[flacial]

Related to #1990

The actual changes were accidentally included in this PR. This PR will serve as a future reference.

Description

Merging this PR will create the page that'll be used to manage flagged & removed exercises. In a subsequent PR, it'll filter removed exercises from flagged and add the filtering input box.

Testing

1. Add exercises from /curriculum/js0/mentor/addExercise
2. Go to the page under /admin/lessons/js0/exercises
3. Make sure remove and unflag actions work as intended (the exercises should refresh upon performing any of the actions)

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c0d3-app	✅ Ready (Inspect)	Visit Preview	Oct 25, 2022 at 1:50AM (UTC)

[flacial]

The changes were accidentally merged in this PR

[codecov]

Codecov Report

Merging #2448 (7740086) into master (3b31d38) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master     #2448   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          185       185           
  Lines         3307      3307           
  Branches       878       878           
=========================================
  Hits          3307      3307           

Impacted Files	Coverage Δ
...es/admin/lessons/[lessonSlug]/[pageName]/index.tsx	100.00% <ø> (ø)

[flacial]

It was reopened to serve the purpose of a future reference.