Add Show / Hide option for Codebase display

[mjherzog]

The data displayed in the Codebase window can be so long that it interferes with getting quickly to the rest of the Project UI data.
This issue is for SCIO v32.3.0.
We should have Hide / Show all options like we have for the Project Data window. That was implemented for #667. I am not sure whether the same technique will work for the Codebase window because is is dynamic file tree.

[pombredanne]

#844 is a dupe of this:

Improve perceived display performance of projects graphs and stats on home page

It can take a long time to display the graphics at the bottom of a project page for large codebase with many packages and resources.

I think we should revisit when and how these are computed and displayed.

• we could pre-compute and cache these computation when a project scans are complete
• we could display these only on request with a click on a toggle button
• we could display these automatically for small projects (say with less than 5K resources) and display on demand otherwise

[tdruez]

@pombredanne I don't see the relation between #800 (codebase panel max-height) and #844 (projects graphs)
Let's have both issues.

[mjherzog]

Since the graphs and stats are static after a Scan is completed I think that it makes sense to compute and cache the stats.