[FEAT] Add /assignment endpoints in course-management

[benjaminkostiuk]

Overview

Implement the /assignment endpoints defined in the API planning document https://github.com/benjaminkostiuk/puff/blob/master/docs/API_ARCHITECTURE.md.

Breakdown

1. Create an Assignment entity based on the ASSIGNMENT table.

• Should have a many to one mapping to courses.
• Can maybe include both the Course object and id as separate fields if that makes things easier.

2. Create an AssignmnentAttribute entity based on the ASSIGNMENT_ATTR table.

• Should be similar to the CourseAttribute entity.

2.5. Create a AssignmentPage and AssignmentAttributePage model.

• You can do this by extending BasePage

3. Create a Assignment & AssignmentAttribute JPA repository interfaces.

• Similar to the Course repositories already created.

4. Create an Assignment service interface and class

• Should be similar to the CourseService already implemented
• Don't forget to throw ElementNotFound exceptions if the associated Course can't be found for an assignment.

5. Create an REST interface for Assignment endpoints

• Similar to the Course REST interface already created.

6. Implement the REST interface with a RestController for Assignment endpoints

• Similar to the Course Controller.
• Don't forget the security and access control on endpoints

7. Write tests for your endpoints (You should also test manually)

• Unit tests for your Assignment service class
• Api component tests for your new apis
• There are already some tests written for Courses that you can go off of.