cubicweb #2105862 add an option to not hide facet body [validation pending]

Currently when clicking on a facetTitle, the corresponding facet body gets hidden. It should be possible to disable that behaviour for an application.

prioritynormal
typeenhancement
done in3.14.3
load0.100
load left0.000
closed by#1fe089765187 [facets] Make hiding facet body optional (closes #2105862), #8663f451c763 [facets] Make hiding facet body optional (closes #2105862)