cubicweb-vcsfile #2748283 remove optional "tags" cube dependency [validation pending]

It currently tags per directory component of each versioned file.

prioritynormal
typeenhancement
done in1.13.0
load0.200
load left0.000
closed by#ec35064baad6 [hooks,tests] remove (silly) tag cube support (closes #2748283)
patch[hooks,tests] remove (silly) tag cube support (closes #2748283) [applied]