New Events: Fix events section

[dihnometry]

• Unified Upcoming and Ongoing sections, and changed the filter to a set of tabs.
• Ensured that if some section is empty, it doesn't render.
• Adjusted minor visual details in Events Cards.
• Added the missing Resources section to the Admin panel and changed a bit of the UI.
• Add new_layout field to Hackathon table to decide which layout to use in each event.
• Use Google Calendar to manage schedules in events.
• Added toast in admin panel to get feedback when creating and updating events.

[vercel]

@dihnometry is attempting to deploy a commit to the Ava Labs Team on Vercel.

A member of the Team first needs to authorize it.