Add a RateTestHandler to analyse Moore rate tests

This handler is designed to automatically analyse the results of Moore output when a ci-test is triggered in a MR.

The primary goal is to produce some plots of the overall rates or lines, like hist_rate.pdf and lines_per_wg.pdf.

Work towards DPA task https://gitlab.cern.ch/lhcb-dpa/project/-/issues/90.

Run the local test:

./run python -m pytest --log-cli-level=DEBUG tests/test_RateTestHandlers.py

Prerequisite

• An executor to run a rate test (similar to throughput test), see lhcb-datapkg/PRConfig!220 (merged).

Functionalities of the handler

• Parse the output log file and obtain rates of each line
• Plot the distribution of rates
• Plot the number of lines per WG
• Compare the rates with those in master
• Post the results somewhere on lhcb-nightlies webpage
• Post some message on the GitLab MR
• Read event sizes and make plots/tables

Future thoughts

• More functionalities will be added into this handler, better to put analysing code somewhere outside the handler?
• To plot the number of lines per WG, line name needs to follow the convention Hlt2/Spruce{WG}_XXX, may need unify this as soon as possible.

needed by LHCbNightlyConf!798 (merged).

cc @rmatev @abertoli