Refactor summarygrid
Refactor summarygrid

By extracting benchmark container generation in a dedicated function for
better readability.

spacetelescope/asv,airspeed-velocity/asv,qwhelan/asv,spacetelescope/asv,spacetelescope/asv,pv/asv,airspeed-velocity/asv,airspeed-velocity/asv,pv/asv,qwhelan/asv,spacetelescope/asv,qwhelan/asv,pv/asv,qwhelan/asv,airspeed-velocity/asv,pv/asv