Refactor AddLinkForm: Class Component → Functional Component

[Manik-Khajuria-5]

Issue

Contributes to #4460

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Description

This PR refactors AddLinkForm.jsx from a legacy class-based React component to a modern functional component using React Hooks.

Key Changes

• Converted AddLinkForm from a class component to a functional component
• Replaced lifecycle methods with useEffect
• Refactored form state handling using hooks
• Preserved existing validation, submission, and async request logic
• Maintained full behavior parity with the previous implementation

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[Manik-Khajuria-5]

@JeffersonBledsoe Can u please review this PR