cubicweb-timeseries #2091050 improve views for "constant" ts [resolved]

The primary view for constant only allow to display the value. It shall display a "normal" primary view without *plot tab* and *values area*

prioritynormal
typebug
done in1.2.1
load1.000
load left0.000
closed by#a1a6f820e276 [views] improve views for "constant" ts (closes #2091050)