[0.5.0-rc.5] Add Course Text & Section Text Endpoint Support

[ewang2002]

• Adds support for course and section text endpoints.

  • Course Text: occasionally, when looking at certain courses on WebReg, there is information displayed for that course (e.g., for CSE 101, there's the text "Students are required to attend a CSE 101 discussion section." that is shown above its entry). This endpoint gets that information for all courses under a subject (e.g., MATH or CSE).
  • Section Text: same idea, but for a specific section (e.g., all of section A).

• Fixes an issue where getting raw WebReg data gives you a string containing the JSON data instead of the JSON object itself.