[Notebook] Differential expression volcano filters should include up-only, down-only options

[bobular]

A request from Kathryn was to add a new user-option on the differential expression notebook for the user to get up-and-down / up-only / down-only regulated genes.

Two ways to do this:

1. add a new WDK parameter and a whole new WdkParamNotebookCell to host its widget - implementation is moderate but the UI/UX footprint is quite large (notebook sections are never particularly compact)
2. figure out how to add a widget to the final step, and where in the eda_analysis_spec to store it. It won't belong to a computation or a visualization!

Back end

Will need backend work too - in ApiCommonWebService

[bobular]

From Ryan

If we already have a search that does that, wouldn't this be a good option for the strategy system? Do your notebook search, then do a regulation search and intersect? Adding parameters to do things that other searches do seems like feature creep. It would also be very inefficient because we stream the EDA results through the process query but to do a regulation check we would have to query the DB for each individual gene, or at least maybe in batches, which is adding some complicated logic (collect a set of genes from EDA, do a search to get regulation and match them up, then deliver one-by-one). We could do it quicker with a second temporary table- that's actually the way I would probably go- but seems like overkill for something the strategy system was designed for, especially this close to release.