CI archive retrieve tests with GFAL2

Problem to solve

Use GFAL2 for transfers in our tests to use the same software stack as FTS.

Stakeholders

Proposal

Several steps:

• start using GFAL2 for xrootd/krb5 retrieves only
  • archive with our standard tests and just write a GFAL retrieve test script that retrieves all files in a specified directory on an eoscta instance from client pod in CI
• Secondly use the same script for http + eos token retrieves
  • CI ctaeos instance must be configured for HTTP and tokens first (see another ticket Julien will work on when back)
• third evaluate relevancy for archives
  • current archive is using heavily xrootd streaming, will be more complicated to move to gfal