Course page API (+ other course API tweaks)

[carolynzhang18]

Notion ticket link

Ticket Name

Implementation description

Steps to test

What should reviewers focus on?

Checklist

• My PR name is descriptive and in imperative tense
• My commit messages are descriptive and in imperative tense. My commits are atomic and trivial commits are squashed or fixup'd into non-trivial commits
• I have run the appropriate linter(s)
• I have requested a review from the PL, as well as other devs who have background knowledge on this PR or who will be building on top of this PR

[github-actions]

Visit the preview URL for this PR (updated for commit d36acbc):

https://extendafamily-7613e--pr89-carolyn-course-page-lh3utj1s.web.app

_{(expires Thu, 09 Jan 2025 22:23:51 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

_{Sign: f8bb7b5cd838ab636347dc54fd0ab08ab3715d31}