SCRUM-7: Integrate Contact Form with Web3Forms API

[tabeebs]

This PR integrates the existing contact form with Web3Forms API, replacing the originally planned backend integration with triggerApi. The implementation provides a complete user experience with form validation, loading states, and appropriate feedback messages.

Changes Made

• Integrated the contact form with Web3Forms API for email submissions
• Added client-side validation for required fields and email format
• Implemented loading state with spinner during form submission
• Added success and error message handling for better user experience
• Set up automatic form reset after successful submission

Why Web3Forms Instead of triggerApi

Web3Forms API provides a simpler, production-ready solution with built-in spam protection and reliable email delivery without requiring us to maintain our own email infrastructure.

Testing Done

• Verified form validation shows appropriate error messages
• Tested successful form submission flow including loading state
• Confirmed success message appears after successful submission
• Verified form resets after successful submission

Important Note for Review and Merge

For testing purposes, the form currently sends submissions to technical@unswdata.com. When approving this PR for merge, please remember to update the recipient email to hello@unswdata.com so that form submissions go directly to the DataSoc Executives when the website is deployed.

Closes SCRUM-7

[tabeebs]

While working on this, I noticed an issue with the Publications dropdown menu in the navigation bar: it disappears when users try to hover from the main "Publications" item to the submenu items. I'll address this in a separate branch/PR for cleaner code organisation.