move operations with path "/v1/test_helpers/*" to test_helpers namespace

[etsai-stripe]

Reviewers

r? @tomer-stripe @vcheung-stripe
cc @stripe/developer-products

Summary

all commands under test_helpers namespace

$ stripe test_helpers --help
Usage:
  stripe test_helpers <resource> <operation> [parameters...]

Available Resources:
  customers
  issuing
  refunds
  terminal
  test_clocks
  treasury

command added to test_helpers namespace invokes expected /v1 path

$ stripe test_helpers treasury received_credits create
{
  "error": {
    "message": "Unrecognized request URL (POST: /v1/test_helpers/treasury/received_credits). Please see https://stripe.com/docs or we can help at https://support.stripe.com/. (Hint: Have you onboarded to Treasury? You can learn more about the steps needed at https://stripe.com/docs/treasury/access)",
    "type": "invalid_request_error"
  }
}

test_helpers added to original command as sub-resource, invokes expected /v1 path

$ stripe treasury received_credits test_helpers create
{
  "error": {
    "message": "Unrecognized request URL (POST: /v1/test_helpers/treasury/received_credits). Please see https://stripe.com/docs or we can help at https://support.stripe.com/. (Hint: Have you onboarded to Treasury? You can learn more about the steps needed at https://stripe.com/docs/treasury/access)",
    "type": "invalid_request_error"
  }
}

test_helpers displayed in the usage of the original command

$ stripe treasury received_credits
Usage:
  stripe treasury received_credits <operation> [parameters...]

Available Operations:
  list
  retrieve
  test_helpers

[vcheung-stripe]

LGTM