Make plots and webpages for hlt2 bandwidth test

Work towards lhcb/Moore#507 (closed). To go with lhcb-core/LHCbPR2HD!242 (merged).

A preview can be accessed here.

• Increased the EvtMax in streamless configuration to 1e5.
• Added a new script, make_bandwidth_test_page.py, where
  • plots of rates, event sizes and bandwidths are made, based on the output of streamless test. Using same plotting script in the RateTestHandler.
  • total rate and bandwidth are computed and saved to a text file. The results will be posted via the handler being added in lhcb-core/LHCbPR2HD!242 (merged).
• Some info are quoted with two $$, which will be further replaced in the handler.
• Minor fixes
  • remove this line

cc @mvesteri @poluekt @rmatev @enoomen