feat(deployment): add basic Deployment resource

[skyscrapr]

Summary

Adds Deployment resource with basic fields. More complete support for Deployments will come in future PRs (see #238).

Related to #238

Depends on #201.

Notes

• API docs: https://app.prefect.cloud/api/docs#tag/Deployments

• This PR is already big, so we're implementing some core fields here and the rest will be implemented in future PR(s)

• CI Acceptance tests are sometimes failing with 503 service unavailable (and sometimes passing), but I tested the newly-added test by hand and it passed:

  $ go test ./... -count=1 -v -run TestAccResource_deployment
  ?       github.com/prefecthq/terraform-provider-prefect [no test files]
  .. etc ...
  ?       github.com/prefecthq/terraform-provider-prefect/internal/utils  [no test files]
  testing: warning: no tests to run
  PASS
  ok      github.com/prefecthq/terraform-provider-prefect/internal/provider/datasources   0.339s [no tests to run]
  === RUN   TestAccResource_deployment
  === PAUSE TestAccResource_deployment
  === CONT  TestAccResource_deployment
  --- PASS: TestAccResource_deployment (3.66s)
  PASS
  ok      github.com/prefecthq/terraform-provider-prefect/internal/provider/resources     4.252s
  

To do

• Run a basic test to create and destroy a Flow + Deployment
• Implement necessary attributes (others can come in a separate PR)
• Ensure current acceptance tests pass
• Expand acceptance tests as necessary

[mitchnielsen]

Thanks for the contribution @skyscrapr 🤝

Now that you've opened #201, could you please remove the Flow-related code to keep this PR focused on Deployments?

[skyscrapr]

Deployments are dependent on flows
You cannot create a deployment without a flow_id.

I split flows into #201. But I'm unsure. How to create this PR if it requires another PR to be merged first. The branch will not pass tests.

If you explain how to do this, happy to update the PR and remove flows.

I have a third PR for deployment access that I haven't opened since it is depending on deployments and only makes the problem worse.

[mitchnielsen]

Thanks for getting this one off the ground @skyscrapr 🤝