Fix query parameter

[svilupp]

Fixes #63

• Fixed a bug in request_body that prevented query argument from being passed to HTTP.jl.
• Updated completion model in the unit tests suite (ada series has been deprecated).
• Added warnings to create_edit that it's deprecated by OpenAI. Disabled tests for get_usage_status and create_edit functions, as they cannot be tested via API.

Note the tests would fail on create_edit and get_usage_status, both are NOT supported anymore and need to be removed in the next minor release.

[svilupp]

Could either of you please review, @cpfiffer and @roryl23 ?

EDIT: I did run tests locally, but I cannot access the repo secrets here to run with my key…

[roryl23]

Thanks for jumping on this! I'll remove the deprecated features after work today