remove notification webhook and send of email

[NicolasMahe]

This pull request involves the removal of several email notification templates and their related dependencies. The changes include deleting the email templates for various events, removing the corresponding imports and configurations, and updating the package.json file to remove unused dependencies.

Removal of email notification templates:

• emails/AccountCreatedReferral.ts: Removed the email template for account creation referrals.
• emails/BidAccepted.ts: Removed the email template for bid acceptance notifications.
• emails/BidCreated.ts: Removed the email template for new bid notifications.
• emails/BidExpired.ts: Removed the email template for bid expiration notifications.
• emails/OfferExpired.ts: Removed the email template for offer expiration notifications.
• emails/OfferPurchased.ts: Removed the email template for offer purchase notifications.

Updates to package.json:

• Removed the @nft/webhook dependency.
• Removed the nodemailer dependency.
• Removed the @types/nodemailer dependency.

Changes to API:

• pages/api/notification.ts: Removed the entire notification handling logic, including imports of email templates, configuration of the nodemailer transporter, and the map of email templates for different events.

Checklist

• Base branch of the PR is dev

[antho1404]

Looks good but make sure to cleanup the env/readme that probably contains these env/features