Fixes for the collapsing of the Data Instances

[neomorphic]

There are some bugs with the collapsing of the "_n" data instances in the console.

1. The regex is only looking for a single digit after the _ so “tiles_10" would not be hidden. Should be an easy fix, but only thought of it after deployment.
2. If you have a bunch of imageblk data instances called “testing_n” and you create an annotation called “testing_n+1” that will get hidden as well. (should be rare case)
3. The show / hide icon is now present at the top of the Data Instance column whether there is something to show or not. (Another easy fix that I thought of after deployment)

[stuarteberg]

In version 3.x of the dvid-console, data instances are not getting collapsed properly.

In the old "diced+dvid" version of the console, a special key (.meta/key/restrictions) was checked to determine which instances should be hidden:

Here's a working example:

• http://emdata.janelia.org/#/repo/mushroombody
• http://emdata.janelia.org/api/node/ee789/.meta/key/restrictions

In the current version of the console, it does not seem to work:

• http://emdata.janelia.org/optic-lobe
• http://35.245.206.210/api/node/73581/.meta/key/restrictions