[Filters] Add filters to DAG View - Backfills Tab

### View
**DAG View – Backfills Tab**

### Filters to Add

- Filter by **Start Date / End Date**
↪ Useful to isolate backfills that targeted a specific data range

- Filter by **Created At**
↪ Helps identify when backfills were initiated (e.g., ad hoc vs. automated)

- Filter by **Completed At**
↪ Enables monitoring of completion lag or stuck backfills

- Filter by **Duration**
↪ Surfaces long-running backfills that may impact system performance

- Filter by **Reprocess Behavior**
↪ Distinguish between missing-only backfills and full-range reprocessing

- Filter by **Max Active Runs**
↪ Useful when diagnosing throttling or concurrency constraints in backfill execution

- Filter by **Status**
↪ Surface failed or incomplete backfills

### API Support

✅ Yes

- `/dags/{dag_id}/backfills` supports filtering via:
- `start_date`, `end_date`
- `created_at`, `completed_at`
- `status`, `table.duration`, `table.reprocessBehavior`, `max_active_runs`

### UI Impact

- Add filter controls above the backfill table (consistent with DAG Runs tab)
- Consider sortable columns and pill filters for behavior or status
- Could also support "re-run" or "cancel" from filtered selection

### Notes

- Users often need to investigate reprocessing activity during incidents
- Filtering helps correlate performance issues with large or frequent backfills