fix: resolve empty enrollment history entries

[waterkimchi]

Description

Fixed the issue where the enrollment history endpoint was returning entries for terms without enrollment data. Now, the endpoint only returns entries for terms with actual enrollment data, ensuring that each entry has at least one data point.

Related Issue

This pull request addresses issue #31.

Motivation and Context

This change is required to prevent unintentional behavior in consumers of the enrollment history endpoint. By ensuring that only terms with enrollment data are returned, we avoid empty data arrays that could cause issues or unexpected behavior in downstream applications.

How Has This Been Tested?

Tested on a local deployment by using the pnpm environment. Minor changes. None affects other code.

Screenshots (if appropriate):

Before(includes the empty data sections):

After(removed the empty data sections):

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.

[andrew-wang0]

Great work! Just a few syntactic changes and it should be good to go 🫡

[andrew-wang0]

Looks Good!