HTTP error message sometimes not propagated

[mitchnielsen]

Summary

While testing #289, I noticed that I wasn't getting the HTTP error message back - just the response code:

Plan: 1 to add, 0 to change, 0 to destroy.
prefect_deployment.deployment: Creating...
prefect_deployment.deployment: Still creating... [10s elapsed]
╷
│ Error: Error creating deployment
│
│   with prefect_deployment.deployment,
│   on main.tf line 42, in resource "prefect_deployment" "deployment":
│   42: resource "prefect_deployment" "deployment" {
│
│ Could not create deployment, unexpected error: http error: Post
│ "https://api.stg.prefect.dev/api/accounts/9a67b081-4f14-4035-b000-1f715f46231b/workspaces/85bad5d0-48ee-42be-9f72-8a2998512d85/deployments/":
│ POST
│ https://api.stg.prefect.dev/api/accounts/9a67b081-4f14-4035-b000-1f715f46231b/workspaces/85bad5d0-48ee-42be-9f72-8a2998512d85/deployments/
│ giving up after 5 attempt(s)

This appears to be related to #286, where the retryable HTTP client we use appears to be swallowing the error.

References

• We may want/need to use https://pkg.go.dev/github.com/hashicorp/go-retryablehttp#ErrorPropagatedRetryPolicy instead of the DefaultRetryPolicy
• Potentially related: Return last not nil response on context Canceled/DeadlineExceeded errors hashicorp/go-retryablehttp#129
• Potentially related: Preserve url.Error/http.httpError Timeout hashicorp/go-retryablehttp#142
• Potentially related: Return the body alongside the status in the baseRetryPolicy in case of error hashicorp/go-retryablehttp#212

Acceptance criteria

• When HTTP-related errors are encountered, the related message is printed out in the Terraform logs