Add support for API keys

[mitchnielsen]

Summary

Context: #255 (comment)

Will there be a Terraform Resource for Account API Keys developed?

I know that there is one for ServiceAccount which in turn gives an API key with a permission set, but that requires to be on a paid version of Prefect. As a developer whom cant afford that at the current moment, I was wondering if you and your fellow incredible devs were thinking about creating that resource? For people whom are lower on the totem pole and are utilizing the lowest tier of Prefect, this Terraform Resource would truly help with credential rotation to keep an environment as secure as possible.

[mitchnielsen]

@scondo-prof - to make sure we're talking about the same API: are you referring to User API key? (api/users/{id}/api_keys)

[scondo-prof]

@mitchnielsen Yes this is indeed what I am talking about!

Also let me add, I am very appreciative of your thorough communication!

[mitchnielsen]

Great, we'll follow up here with any updates on progress.

And thanks, much appreciated! Reach out if you have any other questions/feedback.