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.
added workflow execution functionality
added single request execution possibility
improved workflow execution
added single APICall execution + improved test coverage
Workflow Overview with Workflow views added
WorkflowOverview now is connected to all other widgets
- WorkflowOverview -> Workflow
- WorkflowOverview -> WorkflowRegistrator
- Workflow -> CallRegistrator
- CallRegistrator -> CallSelector