Support Vertex Llama Hosted API Enpoint

[narengogi]

Title:

• Support Llama hosted API Model on Vertex https://console.cloud.google.com/vertex-ai/publishers/meta/model-garden/llama3-405b-instruct-maas

Description: (optional)

• Created transform and config for llama inside vertex
• Handled JSON streaming response

Related Issues: (optional)

• #485

Tests Done:

• Tested streaming for different providers on vertex
• Tested streaming for google and anthropic and vertex google and vertex llama