airflowctl: Add support to manage Task Instances

### Description Currently, `airflowctl` CLI can only manage DAGs and DAG runs. Add support for [task instances](https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html#tag/Task-Instance), so we can easily do bulk operations. Below operations should at least be supported: - [Get Task instances on the basis of different query parameters](https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html#operation/get_task_instances) - [Clear Task Instance state](https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html#operation/post_clear_task_instances) - [Patch Task instance](https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html#operation/patch_task_instance) ### Use case/motivation If there are individual tasks which are in a bad state (hung because of Airflow issue) or just stuck in queued state, it is better to cancel those tasks and reschedule them rather than canceling and rerunning the whole DAG. ### Related issues _No response_ ### Are you willing to submit a PR? - [ ] Yes I am willing to submit a PR! ### Code of Conduct - [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)