cubicweb #5374654 Add count in ETypeFacet labels [in-progress]

Add the number of entities occurrences in ETypeFacet labels

prioritynormal
typeenhancement
done in<not specified>
load0.100
load left0.100
closed by<not specified>
patch[facets] Add the number of entities occurrences in ETypeFacet labels (closes #5374654) [rejected]