Improve dask typing

This tracks untyped Dask APIs that we use.

- [ ] `dask.visualize` is not exported

The following APIs we use in the dask repo are untyped:

- [ ] `da.Array.visualize`/`dask.visualize`
- [ ] `da.Array.compute`/`dask.compute`
- [ ] `da.Array.map_blocks`/`da.map_blocks`
- [ ] `da.Array.map_overlap`/`da.map_overlap`
- [ ] `da.reduction`
- [ ] `da.from_array`
- [ ] Creation methods like `da.zeros`, …