Resolve "Remove cta-taped dependency on eos-client"

Summary

This commit introduces a new RPM cta-eosdf that installs an external script to query the disk system for free disk space. The dependency on eos-client is removed from taped, and instead it is the external script that has a dependency on the eos-client, which it uses to query for free disk space. The path to the script is expected to be provided in the taped configuration. If there is an error getting the free disk space from the script, then no backpressure is applied and the queues are not put to sleep; we still allow staging files for retrieve.

Requires manual tests in pre-production

References

Closes #701 (closed)