Support TIFFs with partial trailing strips

[maxrjones]

The regular chunk grid for Zarr V3 data expects that chunks at the border of an array always have the full chunk size, even when the array only covers parts of it. This is not the case for TIFFs, so we'll be limited to array shapes that are evenly divisible by the tile/strip shape until Zarr supports variable chunk sizes. For now, we'll raise a ValueError if this condition isn't satisfied.