The `workflow.calls` now always contains objects and no more strings
 - `workflow.calls` now contains `call` objects
 - `call` objects have to become models in the future
 - changed workFlowVMSpecs to use scope.workflow._id instead of just id

This commit is a result of a squash commit from @TheBay0r and @EnoF.
Workflows can now be deleted based on ID
 - workflow overview now has a delete button for deletion