Enhance filter section in courseflow feature

[giangnht19]

Description

This PR enhances the unit search functionality in the Course Flow module by adding comprehensive filtering capabilities to help users efficiently discover and select units based on multiple criteria.
Fixes # (issue)

Type of change

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

How Has This Been Tested?

Added dropdown menu filters to the unit search component with the following filtering options:

• Level Filter: Filter units by academic level (1st year, 2nd year, etc.) extracted from unit codes
• Year Filter: Filter units by the year of their teaching period
• Teaching Period Filter: Filter units by semester/trimester (T1, T2, T3, etc.)
• Status Filter: Filter units by active/inactive status
• Search Filter: Text-based search across unit codes and names
• Specialization Filter: Placeholder for future implementation (currently disabled)

Testing Checklist:

• Tested in latest Chrome
• Tested in latest Safari
• Tested in latest Firefox

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have requested a review from @macite and @jakerenzella on the Pull Request