Workflows, triggers etc. should be accessible regardless of workbooks

The idea is to treat a workbook just as a container for any Mistral entities like workflow, trigger, action namespace. User should be able to upload any number of workbooks into Mistral containing some entities and all these entities basically form the same space of accessibility. For example, we upload a workbook containing workflow "Deploy my env" and then we upload another workbook containing a trigger "Deploy my env weekly" that refers to that workflow. At any point in time we can access all uploaded entities, request a list of them and their properties. In this case, a workbook doesn't carry any crucial meaning but rather serves as a dummy container for other entities.