client/graph_view: use transition when setting zoom for visibility
client/graph_view: use transition when setting zoom for visibility

Fixes #339

cben/rhizi,cben/rhizi,ozFri/rhizi,cben/rhizi,tlevine/rhizi,yuvadm/rhizi,shlomif/rhizi,ozFri/rhizi,ozFri/rhizi,yuvadm/rhizi,tlevine/rhizi,Rhizi/rhizi,cben/rhizi,yuvadm/rhizi,shlomif/rhizi,tlevine/rhizi,shlomif/rhizi,tlevine/rhizi,ozFri/rhizi,shlomif/rhizi,yuvadm/rhizi,Rhizi/rhizi,Rhizi/rhizi,Rhizi/rhizi