Support `nativemax` and `nativemin` as space resolutions

[tsalo]

What would you like to see added in this software?

This stems from PennLINC/qsiprep#681, as DWI reconstruction tools require isotropic voxels, but native voxel sizes aren't always isotropic, so our idea was to accept nativemax and nativemin options.

Do you have any interest in helping implement the feature?

Yes

Additional information / screenshots

No response

[effigies]

Maybe the way to go here is to provide an API to register a space, e.g.,

ReferenceSpaces.register(
    'nativemin',
    Description='Data resampled to isotropic voxels matching minimum of native voxel sizes',
)

Then downstream workflows do not need to rely on releases to get the features they need.

[tsalo]

That sounds good!