Provides the raw endpoints to Infusionsoft's XML API for Webform actions.
https://developer.infusionsoft.com/docs/xml-rpc/#webform-retrieve-a-form-s-html
https://developer.infusionsoft.com/docs/xml-rpc/#webform-retrieve-webform-ids
@spec retrieve_a_forms_html(integer(), String.t()) :: {:ok, list()} | {:error, String.t()}
@spec retrieve_webform_ids(String.t()) :: {:ok, list()} | {:error, String.t()}