Implement Course Requirements for Undergraduate Majors

[Awesome-E]

Description

• Splits the search sidebar in the roadmap to "Major" and "All Courses"
• Provides the option to select from existing majors using data from the API
• If the selected major has specializations, provides the option to select a spec
• When a major (and spec if present) is selected, a required course list will be shown

Screenshots

Test Plan

This PR is work in progress

Issues

Closes #568

[CadenLee2]

Overall functionality

• Although majors don't save locally when not signed in, this doesn't seem like a major inconvenience (considering that a user hoping to work on their roadmap long-term would probably sign in)
• Because the course titles alone in the major requirements list don't show past quarter offerings, I think that makes it impossible to see quarter offerings on the desktop roadmap without using the All Courses/search menu. This probably increases the importance of our planned change of moving past quarter offering information to the popover

Styling Details

• Is the green color for completion of a group requirement finalized or just a temporary placeholder? I noticed it's just the default green and didn't see an example of what it should look like on the Figma, and it stands out a bit since there isn't much green elsewhere on the roadmap
• Rare long course names like ANTHRO121AW still stick out slightly from their cells. You had mentioned a while ago that it doesn't scale font size "yet"--is this a goal, or will we keep the font sizes the same?
• Noticed that certain other course titles wrap (see CHC/LAT132B under History B.A. History spec)
• The major/spec dropdowns use a different blue color that doesn't match the rest of PeterPortal (is it from the react-select default style?). Additionally, in dark theme, the text on the selected blue item is black, as opposed to the white-on-blue we have elsewhere.

For the most part, the changes work well:

• Clearing requirement groups works
• Major saving to my account works, including with multiple roadmaps
• Tested various majors (with and without specializations); signed in and signed out; desktop and mobile; multiple roadmaps with different majors per roadmap
• Didn't fully inspect all the code closely, but at a glance the file structure (such as how the sidebar is organized) looks good and major changes make sense