Support size-1 non-scalar inputs to crop OR provide more helpful error

[DanRyanIrish]

Describe the feature

NDCube.crop takes tuples of scalar high-level coordinate objects. But when length/size-1 objects are put in, a very unhelpful error is given.

Request that either NDCube sanitizes the inputs and converts them to scalar if length-1, and/or provide a more helpful error.

Proposed solution

No response

[hayesla]

Ok just for context (for my silly brain), this doesnt work before the open PR:

cube.crop(lower_corner, upper_corner)

but this worked:

cube.crop((lower_corner.squeeze(),), (upper_corner.squeeze(),))

[DanRyanIrish]

cube.crop(lower_corner, upper_corner)

Whereas this should work in the PR

[DanRyanIrish]

Resolved by #863