Automatic merge from submit-queue (batch tested with PRs 39538, 40188, 40357, 38214, 40195)

Decoupling scheduler creation from creation of scheduler.Config struc…

**What this PR does / why we need it**:

Adds functionality to the scheduler to initialize from an Configurator interface, rather then via a Config struct.

**Which issue this PR fixes** 

Reduces coupling to `scheduler.Config` data structure format so that we can proliferate more interface driven composition of scheduler components.