Allow for cell and nucleus detection

[lacan]

It often happens that people are interested in obtaining cell outlines plus nuclei in order to obtain compartment-based measurements

Describe the solution you'd like
Considering cellpose just added a new series of models for denoising that can be "overlapped", would it be possible to do the same for obtaining both the cell outline and the nuleir outline on the same cellpose run?

Describe alternatives you've considered
We currently run cellpose twice to detect both compartments, then do a bit of morphology to associate them with one another, but having this built in could be great!