DerivationFrameworkPhys: import PHYSLITE variable descriptions
This MR imports the CSV files for the PHYSLITE variable descriptions from a personal gitlab repo into the more official location of the DerivationFrameworkPhys
package and allows everyone to easily update these.
These descriptions are used subsequently to automatically build the webpages linked from https://atlas-physlite-content.web.cern.ch/ from the daily TrfTestsARTPlots
ART tests.
Tagging @jcatmore, @jchapman, @ekourlit, @gwatts, @nozturk for info a further feedback.