Align task tags in dataset metadata
## Describe
Once we have agreed on a common naming for task tags for all open source projects, we should align on them.

## Steps
- [x] Align task tags in canonical datasets
  - [x] task_categories: 4 datasets
  - [x] task_ids (by @lhoestq)
- [x] Open PRs in community datasets
  - [x] task_categories: 451 datasets
  - [x] task_ids: 556 datasets

