Make test polling intervals and timeouts configurable

Replace hardcoded values with four new options in the [optimize] config group:

• model_check_interval (FloatOpt, default 1.0s): poll interval for wait_for_instances_in_model, wait_for_instances_attributes_in_model, and wait_delete_instances_from_model.

• resource_check_interval (FloatOpt, default 1.0s): poll interval for all call_until_true() sleep_for= arguments and the time.sleep() call in the generic wait_for() helper.

• resource_timeout (IntOpt, default 300s): replaces all hardcoded duration= arguments to call_until_true() across API, scenario, and client-functional tests. Also drives the compute-node trait-removal retry count.

• model_timeout (IntOpt, default 300s): replaces the timeout=300 default parameter in the three model-wait helpers.