cubicweb #968823 [facets] select "no value" [resolved]

Sometimes it can be usefull to select in the facets of searches all the elements that have to value for an attribute.

For example, on a JPL I search for a bunch of tickets, then I want to select all those that are not included in any version.

done in3.10.0
load left0.000
closed by<not specified>