API Version Hard-coded in Client

[sjbodzo]

The api version used for the various calls in the client package is hard-coded. The version is inconsistent between some of the calls, such as between the firewall rules enforcer orchestration.

Proposal: If the API version should be consistent for all issued calls, pass in a version parameter to the Client struct. If they differ per endpoint due to functionality of the product, pass in versions for for each relevant product functionality to the Client struct.

This will decouple the API version from the provider logic, allowing good defaults and supporting customers in the future who may require calling different API versions.