What does this PR do?

Initializes the Klaviyo piece using the latest V3 API.

• Authentication: Implements API Key auth with validation.
• Architecture: Uses a centralized common module to handle V3 specific headers (revision: 2024-02-15) and strictly typed HttpMethod enums.
• Action: Create Profile - Fully mapped to the V3 /profiles endpoint with validation for Email/Phone requirements.

Explain How the Feature Works

The piece uses the klaviyoCommon helper to inject the required revision header into every request, ensuring compatibility with the latest Klaviyo infrastructure.

Relevant User Scenarios

• Syncing new leads from Typeform/Facebook Leads directly into Klaviyo.
• Automating profile creation from e-commerce checkout events.

Build Proof

Video of successful local compilation: https://youtu.be/WbjK-M9HGfo

Fixes #8284 /claim #8284