remove use of HTCondorUtils.AuthenticatedSubproces

[belforte]

it was needed when TaskWorker was using multiple X509 proxies at same time and needed to submit to schedulers with the user's proxy.

Now that we submit using a single service token, w/o GSI, there's no need anymore

This is needed in order to progress on #8272

[belforte]

So far done in DagmanSubmitter and it works.

[belforte]

modified code for DagmanSubmitter is in my branch https://github.com/belforte/CRABServer/tree/stop-using-authenticated-subprocess-8277
I am not sure if possible errors are properly handled in this version, in particular I am trying to avoid returning a clusterId incase schedd.submit works but schedd.spool fails.