fix: revert code due to wrong merge conflict resolution

[rpenido]

Description

The #799 PR inadvertently reverted the code change from #815. This PR adds the code from #815 again.

Testing instructions

Setup:

1. Create test taxonomies, tags, orgs, and courses with https://github.com/open-craft/taxonomy-sample-data/
2. Run this PR's branch for course authoring.

Testing Tag Drawer:

1. Login to Studio as a non-superuser with course authoring permissions.
2. Visit the Sample Taxonomy Course course-v1:SampleTaxonomyOrg1+STC1+2023_1
3. Navigate to a Unit
4. Click "Manage Tags", either from the sidebar or the unit's menu
5. Add a bunch of tags at various hierarchy levels, and ensure they add as expected.
6. Delete some tags and ensure they delete as expected.

[openedx-webhooks]

Thanks for the pull request, @rpenido! Please note that it may take us up to several weeks or months to complete a review and merge your PR.

Feel free to add as much of the following information to the ticket as you can:

• supporting documentation
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All technical communication about the code itself will be done via the GitHub pull request interface. As a reminder, our process documentation is here.

Please let us know once your PR is ready for our review and all tests are green.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (815ddbe) 90.77% compared to head (39dde60) 90.78%.
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #824      +/-   ##
==========================================
+ Coverage   90.77%   90.78%   +0.01%     
==========================================
  Files         535      535              
  Lines        9255     9255              
  Branches     1991     1991              
==========================================
+ Hits         8401     8402       +1     
+ Misses        829      828       -1     
  Partials       25       25              

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[xitij2000]

Tested, works fine.

[openedx-webhooks]

@rpenido 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.

[rpenido]

Thank you @xitij2000 !