K6 teardown()

[thim81]

Feature: Provide a converter option to insert custom K6 "teardown()" logic, that will be injected during conversion.

Reasoning: K6 supports a life cycle: https://k6.io/docs/using-k6/test-life-cycle/
The postman-to-k6 package already supports the “pre-request” functionality from Postman, but it feels that “setup()” and “teardown()” is not a concept that exists in Postman, and it serves more the K6 execution.

Approach: Provide a file reference as a --k6-teardown CLI parameter, that will be take the content of the file and insert it in the generated K6 script.