Integrate with CRIC to fetch list of Datalake endpoints to test

[andreaceccanti]

This JSON document provides a list of active RSEs in the Datalake.
We can fetch the list of endpoints to test starting from the list of RSEs, however we should probably use a different prefix for each endpoint to not mess with RUCIO data.

[federicaagostini]

The fetch-rses-from-cric.sh script provides the list of datalake endpoints in yaml syntax compliant with the variables.yaml file.

• Updated variables.yaml file with CRIC datalake endpoints
• Added endpoint.<endpoint_alias>.path.prefix key to variables.yaml file, which match the RUCIO path (i.e. rses.<endpoint_alias>.protocols[0].prefix of JSON document)
• Added Get ESCAPE path keywork to get correct ESCAPE path from prefix
• Added warning message in CI if there are new CRIC RSEs (here), filtering by .rses.<endpoint_alias>.name
• Updated README accordingly

[federicaagostini]

Integrated dynamic fetch of CRIC endpoints in CI (this commit):

• locally (i.e. using run-testsuite.sh): run endpoints listed in variables.yaml
• CI (i.e. using ci/run.sh): run endpoints listed in variables.yaml and new CRIC endpoints