CM: Add Host to Host to storage model and isolate UpdateCall

[michaelschnyder]

Currently there is only a PID Property in a JobRun an it needs to be updated as whole with potential race conditions RAW/WAR. In addition, the Host property is missing on the model.

• Update database schema to support host (should have been done by @olibanjoli)
• The storage provider should provide an exclusive method to update/set the PID and Host
• The Host should be part of the model in CM-Storage
• Also Update the CM-Management to be able to show the host there.