Consider inferring ufunc output dimensions/sizes/dtypes

[aazuspan]

Currently Image.apply_ufunc_across_bands requires that output dimensions, sizes, and dtypes are explicitly defined. To simplify usage, we could consider running a small piece of test data through the ufunc and inferring those parameters. This approach is taken by dask.array.apply_gufunc via apply_infer_dtype.

We may find there's a good reason that Dask doesn't attempt to infer dimensions or sizes, but I think this is worth a closer look.

[grovduck]

Nice, I'll be curious about what you find here.