Adds a new integration for Resend, an email sending service.
Includes:
- Resend API credential (`ResendApi.credentials.ts`) for API key authentication.
- Resend action node (`nodes/Resend/Resend.node.ts`):
- Supports "Send Email" operation with parameters for to, from, subject, html, text, cc, bcc, reply_to, and tags.
- Uses Resend API `https://api.resend.com/emails`.
- Resend trigger node (`nodes/Resend/ResendTrigger.node.ts`):
- Handles Resend webhooks for various event types (email.sent, email.delivered, etc.).
- Implements webhook signature verification using Svix and a user-provided signing secret.
- Allows you to select which events to listen for.
- Official Resend SVG icon (`nodes/Resend/Resend.svg`).
- Adds `svix` as a dependency for webhook verification.
