refactor: update controller

[jwsmith24]

Everything from #97 plus:

• refactored update logic and consolidated to rubricController
• remove template-related controller files to reduce clutter
• grouped request and response files for the canvas api in palette-types

[jwsmith24]

latest push adds the first round of frontend refactoring to better align with the Canvas API while maintaining a nice UX

[jwsmith24]

still WIP to address previous issues

[jwsmith24]

Reorganized duplicate rubric handling on the frontend to align with new design pattern.

Next phase will be updating the protocol modules to ensure the course and assignment associations are applied properly.

[jwsmith24]

Also added a simple loading component to display during fetches!