Make https://wcsim.github.io/Validation/ more user-friendly

[tdealtry]

It's sometimes non-trivial to lineup the travis job ID with the physics plots to check at https://wcsim.github.io/Validation/ (e.g. when the build is triggered by a Validation commit, rather than a WCSim commit). Some suggestions (some may not be possible of course):

• Add a build start time column
• Use a hyperlink to the relevant WCSim github page for the commit ID and/or description column
• Add a link to the GitHub actions page
• Split webpage out by action number (rerunning an action updates the webpage so the previous run is lost, and the colours are never updated). This is non-trivial, as this won't work when only re-running failed jobs with the current system (where a new webpage is built on the build job)
• Add WCSim output file size comparison to validation webpage (maybe as a %)
  • Should run something like printSizes.C so can see finer details in the CI logs too
• Add WCSim runtime comparison. The run time for comparison CI jobs is put on the webpage, but the reference runtime is not measured or saved.
  • Note that runtime depends on specific node performance, so could vary wildly. Look into whether there is a "node performance scale factor" in github actions, as there is on the grid
• Navigating around plots to see which are different and which are not, and how different they are, is time consuming. Think about
  • whether a summary table of which plots are not exactly identical & statistical measures of differences (e.g. mean value % change) is useful
  • whether navigation could be improved by adding a link back to the job page from the plots page (currently, if you look at 20 plots, you need to click "back" in the browser 20 times to go back to the job summary page). I think this is a no brainer