Backport: Add _retry_server_directed_only mode for Retry-After header compliance#757

sd-db wants to merge 6 commits intorelease/v4.1.5databricks/databricks-sql-python:release/v4.1.5from

sd-db/PECOBLR-1863/retry-server-directed-only-v4.1.5databricks/databricks-sql-python:sd-db/PECOBLR-1863/retry-server-directed-only-v4.1.5Copy head branch name to clipboard