Count the actual number of http requests to NetBox instead of retried requests

Since http requests to NetBox use an http client with retries, the actual number of http requests can be bigger than the number of `client.Do()` invocations. This is relevant for
- rate-limiting
- metrics collection

Instead of on every `httpClient.Do()`, waiting (for rate-limiting) and incrementing total number of requests should happen in [RequestLogHook](https://pkg.go.dev/github.com/hashicorp/go-retryablehttp#RequestLogHook).