sunburst improvements

[williaster]

this commit adds some additions to the sunburst vis:

• trim '0' groups from sunburst paths to show null groups (previously, all levels were filled in completely with filler groups even if the counts were 0; those should have been trimmed)
• add ability to map color to sunburst groupby groups, instead of ratio. Until we refactor controls, this was implemented simply by checking if m1 == m2.
• add fancier breadcrumbs to sunburst re derek's request

trickiest part was making sizing of breadcrumbs etc dynamic based on the number of levels and within a dasboard, but tested it a fair amount.

[landscape-bot]

Repository health decreased by 0.44% when pulling 0608094 on chris/sunburst-fixes into 2aa0e0d on master.

• 8 new problems were found (including 0 errors and 8 code smells).
• 8 problems were fixed (including 0 errors and 8 code smells).

[mistercrunch]

With long text there's some issues in the breadcrums, it's hard to ensure that it all fits in there, the colors of the breadcrum also don't match the chart.

When not hovering there's an issue of white on white because of the lack of borders. White could mean that it doens't exist or that it's just a median ratio...

[landscape-bot]

Repository health decreased by 0.44% when pulling 3197c4b on chris/sunburst-fixes into 2aa0e0d on master.

• 8 new problems were found (including 0 errors and 8 code smells).
• 8 problems were fixed (including 0 errors and 8 code smells).

[landscape-bot]

Code quality remained the same when pulling 3dc9996 on mistercrunch:chris/sunburst-fixes into 2aa0e0d on mistercrunch:master.

[williaster]

all right! this is what it looks like now. I think wrapping of breadcrumb text will still be gnarly beyond 2 lines but this is much better. at that point they should just increase the size of the chart on the dashboard.

[mistercrunch]

LGTM !!!