[PROPOSAL] - Add missing high-level client methods for handling API Guide examples.

[Djcarrillo6]

What/Why

What are you proposing?

Currently the some of the API methods related to composable templates do not yet exist in the high-level client, they only exist as methods on the low-level client. This proposal seeks to add the missing methods to the high-level client so that the low-level client examples in the /guides/index_template.md can be replaced with the high-level client implementations.

What problems are you trying to solve?

By adding the missing methods to the high-level client, this would allow for updating the API action guides to use the more C# friendly implementation via the high-level client.

#OSCI-2023