Modernize instructor course admin staff page

[mylesw27]

This PR intends to convert the instructorCourseAdminStaff page from Javascript and EJS to TypeScript and HTML template literals.

[github-actions]

All images

Image	Platform	Old Size	New Size	Change
prairielearn/executor:4fb7f4281eabbfdf430e89282d53fef1985fdeae	null	1645.00 MB	1645.01 MB	0.00%
prairielearn/prairielearn:4fb7f4281eabbfdf430e89282d53fef1985fdeae	linux/amd64	1645.01 MB	1645.01 MB	-0.00%

[nwalters512]

I'm blocking on the global hasUnknownUsers variable.

[codecov]

Codecov Report

Attention: Patch coverage is 98.21429% with 14 lines in your changes are missing coverage. Please review.

Project coverage is 66.76%. Comparing base (6cf6a1e) to head (4fb7f42).
Report is 1 commits behind head on master.

Files	Patch %	Lines
...ourseAdminStaff/instructorCourseAdminStaff.html.ts	98.26%	13 Missing ⚠️
...ctorCourseAdminStaff/instructorCourseAdminStaff.ts	96.96%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9822      +/-   ##
==========================================
+ Coverage   66.43%   66.76%   +0.33%     
==========================================
  Files         453      454       +1     
  Lines       70289    71020     +731     
  Branches     5648     5676      +28     
==========================================
+ Hits        46694    47414     +720     
- Misses      23170    23182      +12     
+ Partials      425      424       -1     

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