workflow View Model implemented basic functionality
* getWorkflow
* postWorkflow
* putWorkflow
* getAvailableCalls
workflow api calls implemented
* getWorkflows
* getWorkflowById
* registerWorkflow
* saveWorkflow
workflowRegistrator widget created
- additional rest calls are not yet connected
updated api url from 'api/workflow' to plural 'api/workflows'
switched to mockgoose for mongo mocking
Move the `getAvailableRequests` to `restCallVM`
Call Selector added and Registration of Workflow works e2e
 * the Workflow is intended to be included in an other widget/page/view, therefor the widget will not handle the success page.