Add additional parameters to cellfinder napari UI

[alessandrofelder]

# TODO: params to add
NETWORK_VOXEL_SIZES = [5, 1, 1]
CUBE_WIDTH = 50
CUBE_HEIGHT = 20
CUBE_DEPTH = 20

Created based on TODO in code.

[alessandrofelder]

@adamltyson are the above the only parameters that need adding to detect?
Are there parameters that need adding in train and curate?
And where in the GUI should they go?

[adamltyson]

Both detect and train should (as far as possible, practicable) have the same parameters as the functions they call in cellfinder-core. Descriptions for docstrings can be found in the existing CLI tools (detect, train).

The extra parameters could probably just be added to the bottom of the corresponding widgets. Maybe an "advanced" section could useful.

curate is a GUI-only tool, so nothing to add.