Issue 106 | Finished Candidate management system

[Flapjacck]

This pull request adds a new endpoint to update a candidate's status and enhances the candidate retrieval API with an availability filter. The changes improve both the flexibility of candidate queries and the administrative capabilities for managing candidate statuses.

New endpoint for updating candidate status:

• Added updateCandidateStatus controller to allow admins and interviewers to update the status of candidates within their team, with input validation and proper permission checks (updateCandidateStatus.ts, candidateRoutes.ts, candidateValidators.ts). [1] [2] [3] [4]

Enhancements to candidate retrieval:

• Added optional hasAvailability query parameter to the getCandidates controller, enabling filtering of candidates based on the presence of availability records (getCandidates.ts). [1] [2]
• Included Availability model in getCandidates.ts for the new filter functionality.

Exports and imports:

• Exported the new updateCandidateStatus controller from the candidate controllers index (index.ts).

Validation improvements:

• Added a Zod schema for validating candidate status updates (candidateValidators.ts). [1] [2]

Closes #106