Scheduler: Building Block & Control Plane Service

[cicoyle]

This PR adds the relevant code for:

1. a new Scheduler Building Block
2. a new Scheduler Control Plane Service

This PR follows this official proposal, however we did implement bidirectional streaming between the Scheduler and Daprd Sidecar (the proposal will be updated to reflect this change).

This is an end to end solution where an app is able to schedule a job to the daprd sidecar and perform basic crud operations with the job. The daprd sidecar sends the job to the Scheduler control plane service, which then stores the job in its embedded etcd. At trigger time, the scheduler will send the job back to the daprd sidecar where the sidecar will send the triggered job along to the app.

This includes work to replace the actor reminder subsystem, by scheduling the actor reminders in the Scheduler control plane service embedded etcd.

Perf numbers will be provided soon.

There were several individuals involved in making this work happen - thank you to all 🚀

Issue reference

1.14 release P0
Here is the issue tracking the work. There are a few remaining items that will be completed before the release date.

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Unit tests passing
• End-to-end tests passing
• Extended the documentation / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#[issue number]
• Specification has been updated / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#[issue number]
• Provided sample for the feature / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#[issue number]

[cicoyle]

Sorry for the confusion - I reset my old branch and am closing this PR and opening another with the feat-dist-scheduler branch instead of my backup