[RTA/DPA BW tests]: Minor patches

FYI @lugrazet @shunan

• New page with rates per stream and per WG,
• Add a few new WG assignments for lines to match up with sprucing pass-through streams,
• Drop the same raw banks in the pass-through sprucing for the per-WG turbo bar chart
• Fix the pie chart legend?
• Get rid of the per-WG plots?
• #13: better name for --multiple-processes arg
• Headline bar charts with TDR equivalents

Also fixing a broken link in lhcb-core/LHCbPR2HD!280 (merged)