[EOS] Modify STAGE polling (GET) logic to take into account files not queued on CTA
This CTA issue matches the following Jira issue on EOS: https://its.cern.ch/jira/browse/EOS-5429
During the last tape REST API test (https://gitlab.cern.ch/cta/operations/-/issues/894), we noticed that due to the STALL rules in place, the files to stage could not be queued to CTA.
There is currently nothing in place in the STAGE polling to check whether a file was queued on CTA side or not. Currently, if a STAGE request contains files that could not be queued on CTA, these files will just be considered by the client as files being processed by CTA.
One should just add a check during the polling. If the file is NOT on disk and has not been requested on CTA, then an error should be set for this file before being returned to the client.
Internally, the STAGE polling is using the xrdfs query prepare
logic. So you can just use the value of the field "online" and "requested".