Set up ConditionStore in core athena

This MR sets up the ConditionStore in basic serial jobs. It was already there in AtlasThreadedJob, but not in AtlasUnixStandardJob, instead appearing in a conddb import. This is also added back to the CA version, where I removed it (in error) for consistency.

tagging @jchapman and @tsulaia

Cheers,

Stewart