Fix: Consolidating Course Data Models

[matt-franklin225]

Description

Removed redundant GE variable created in courses.ts of the api's schema, importing that variable from lib/course.ts instead. Updated the names of the matching variable in other files that use this variable to inputGECategories for consistency.

Related Issue

Will close #142

Motivation and Context

This cleans up redundant code in the codebase.

How Has This Been Tested?

The changes have been tested on a local instance.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code involves a change to the database schema.
• My code requires a change to the documentation.

[matt-franklin225]

There really weren't many duplicate data models so I just left it as is (excluding the duplicate ge variables)