adding Klarna agent as an example using OpenAPI chain

[kreneskyp]

Description

This PR adds @klarna agent. This agent is an example using the OpenAPI+OpenAIFunctions chain to fulfill a user request with an LLM chosen API call.

The chain also demonstrates how to format the JSON response into markdown.

Changes

• adds klarna_v1 fixture
• adds klarna_v1 to dev_fixtures make target

How Tested

This bot was used to test OpenAPI+OpenAIFunctions. It is subsequently tested by dev_setup test workflow.

TODOs

[List any outstanding TODOs or known issues that still need to be addressed.]