Create workitems on Semantic models

I want to give this idea a much-needed boost: even though the new release makes it less likely to run into corruption / clashes as Semantic Models have separate repositories, there is also a raised likelihood for larger models that cover more reports and therefore may more often be worked on by more than one developer.

Given that a pending Work Item on a Semantic Model would also tell you something about how “safe” it is to touch the data going into the model, this is a dangerous omission in larger deployments.