Added showAll option for the Search page as a tri-state checkbox

[HeidiTao]

Description

Added showAll option for the Search page as a tri-state checkbox, based on the show settings of FCEs, Course Info, and Schedules.

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Trying out different combinations of show selections for FCEs, Course Info, and Schedules, for both logged-in users and guests.

Test Configuration:

• Node.js version: v20.16.0
• Desktop/Mobile: Desktop
• OS: Windows
• Browser: Chrome

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[railway-app]

This PR was not deployed automatically as @HeidiTao does not have access to the Railway project.

In order to get automatic PR deploys, please add @HeidiTao to your team on Railway.