[BUG] Chunking limits

[talonchandler]

Computing a phase transfer function with size > 2048 x 2048 x 110 results in an error:

ValueError: Codec does not support buffers of > 2147483647 bytes

which is because we're creating chunks that are too large.

mantis is solving this problem by limiting the chunk sizes to 500 MB in the create_empty_zarr function. I chatted with @edyoshikun, and he has long-term plans to merge recOrders and mantis's create_empty_zarr functions so that this code can be reused. Maybe create_empty_zarr should be an iohub utility?

Related: a suggested rechunking utility for iohub czbiohub-sf/iohub#184