Investigate unifying JLab 2.0 and JLab 3.0 in a single package about monorepo

[naterush]

Ok, so we can certainly include both of the files in the labextension folder. The main question is: if we just copy the .tgz into the labextension folder, how do we make it so jlab 2 actually discovers the lab extension?

I think it might have to do with the keywords in the setup.py, which gets put in the metadata. Can we put all of these words? If so, what happens?

[naterush]

If we do this successfully, we can get rid of the mitosheet2 package. We would just be left maintaining the mitosheet and mitosheet3 packages (and the latter only because most of our active users are on this one).

More than that, though, this might be able to simplify a lot of our build process. We will see. I def want to figure out if this is possible.