cubicweb #2930356 integrate a pictogram font [validation pending]

in order to have a standard set of icons available in cubicweb-web. I propose to use the entypo font already used by cubicweb-tracker

prioritynormal
typetask
done in3.18.0
load0.250
load left0.000
closed by#cf21813d7003 [css] add the entypo font as available ressource (closes #2930356)
patch[css] add the entypo font as available ressource (closes #2930356) [applied]