R1:742c3a834fc5

Provide UI hints about task subtypes

Summary:
Ref T12314. Open to counterdiffs / iterating / suggestions / skipping most or all of this, mostly just throwing this out there as a maybe-reasonable first pass.

When a task has a subtype (like "Plant" or "Animal"), provide some hints on the task list, workboards, and task detail.

To make these hints more useful, allow subtypes to have icons and colors.

Also use these icons and colors in the typeahead tokens.

The current rule is that we show the subtype if…