Standardize customerManagedCloud worker API url naming #577
Description
To configure a worker for a customer-managed Prefect instance, both worker.customerManagedCloudApiConfig.cloudApiUrl and worker.customerManagedCloudApiConfig.apiUrl have to be set to the same value, which isn't very intuitive and does not follow the same pattern as workers for other types of Prefect servers.
apiUrl as constructed in _helpers.tpl should be the fully constructed URL that the worker polls (including both the account and workspace IDs for cloud and customer-managed). However, on L74, the apiUrl that is passed in is expected to be just the base URL and then is used along with the account/workspace IDs to construct the output URL. Naming the input differently or using cloudApiUrl to build the URL would make the pattern consistent with cloud workers.
Additionally, we should update the README/validation if cloudApiUrl is a required field for customer managed workers.