Task names character limit in workflows

[vvsivaprasadreddy]

The databricks task names are generated as combination of dag_id and task_id in notebook operator but this will overflow the character limit in workflow jobs, which has only 100 characters limit. Need a change in ‎_get_databricks_task_id to return the trimmed task id if the taskgroup is workflowtaskgroup type.

This will also give cleaner look on the databricks UI to easily identify the task names.