Us/10: Update fetching methods to match new API

[thclmnt]

Add new API calls into the application from the new CELCAT API.

Notable changes:

• Use of a proxy to redirect requests to CELCAT API without worrying about certificates on mobile
• Format fetched data to match old API format, with some minor modification
• Adapt CourseRow component to display information from the new API (removed icons in favor of a formatted description)
• Adapt Day & Week component to use new fetch methods
• Refactor Week component to generate both week and year number, to improve API requests
• Minors update to the stylesheet
• Formatted some old files