"Queue up new tasks" equivalent in CLI / REST API

### Description Suggestion to add a new command in the CLI / REST API to reproduce the "Queue up new tasks" action that can be trigger within the web UI, with `start_date` and `end_date` parameters to allow running this action accross all dag runs lying a given period. For the CLI, it could be `airflow dags queue_up_new_tasks` or `airflow dags reload` for instance. ### Use case/motivation Right now, when we add new tasks to an existing dag containing existing dag runs, it is not straightforward to run these newly added tasks in the existing/previous dag runs. Two workarounds : - `airflow dags backfill` but not satisfying as it transforms "scheduled" existing dags run into "backfill" dag runs, which prevent us from interacting with them through the web UI (like clearing tasks, etc.) - `airflow tasks render` followed by `airflow tasks clear` but it is not convenient as the `render` command is only working for one specific execution_date (or run_id) at a time. Or maybe there are already solutions par that ? ### Related issues https://github.com/apache/airflow/discussions/30435#discussioncomment-8856597 ### 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)