R1:ee54e71ba9aa

On workboards, link ancestor project breadcrumbs to their workboards

Summary:
Ref T13269. Currently, if you're on a milestone workboard like this:

> Projects > Parent > Milestone > Workboard

The "Parent" link goes to the parent profile. More often, I want it to go to the parent workboard. Try doing that? This is kind of one-off but I suspect it's a better rule.

Also, consolidate one billion manual constructions of "/board/" URIs.

Test Plan: Viewed a milestone workboard, clicked the parent link, ended…