HUE-1656 [oozie] Make data fully integrated in the API part 2
HUE-1803 [oozie] Support global configuration

Workflow global properties are split in two parts:
  - regular properties
  - config
[oozie] Front end for SLA

Remove model during serialization phase and use view model.
Merge remote-tracking branch 'origin/HUE-1657-sla-search' into HUE-1657-sla-search