All CLI calls read from zarr

[talonchandler]

Fixes #42.

This is a quick PR that integrates work I did last month to generate bleaching curves from hummingbird.

• reads directly from zarr for estimate-bleaching and estimate-deskew (instead of the interim read_micromanager from before)
• uses the channel names and iohub's channel_display_settings to plot with better colors

IMO you can give this a cursory review @edyoshikun, since this doesn't interact with much of the rest of the pipeline.

I've tested manually on several datasets.