[keepercore] topic/workflows -> allow to filter by criteria like cloud/account

[lloesche]

The task queue allows filtering by attributes. E.g. if a worker tells the core that it can apply tagging for cloud aws then it would receive tag tasks for cloud aws account 123.

In workflows we currently don't have a similar filter criteria. It's just a "collect" or "cleanup" workflow. Not a "collect aws" or "cleanup aws account 123" workflow.