Avoid similar name confusion between autogenerated files and client wrappers

[UZ9]

Juno's SDK primarily consists of two parts:

• The autogenerated files from OpenAPI
• Wrappers for each service to handle validation, authentication, etc.

However, these two files have very similar names:

• <Service>Api (autogenerated) vs <Service>API (wrapper)

This can especially be confusing if we're doing any sort of documentation generation:

As such, we'll likely need to switch the wrapper classes to a name other than an API suffix. One idea might be changing it to <Service>Client for wrappers:

• EmailClient
• AuthClient
• UserClient
• ...etc.