R1:c46be2a70b4d

Allow Maniphest tasks to be queried by workboard Column PHID via SearchEngine

Summary:
Ref T13120. See PHI571. Fixes T5024. This adds a "View as Query" action to workboard columns, which builds a query in Maniphest that has the current query constraints plus an additional constraint to select only tasks in the specified column.

This is a normal query and can be turned into a dashboard panel, added to a menu, edited, saved as a link, etc.

Much of the complexity here is that finding tasks in a given…