Background activities scheduling was moved to its own middleware where the actual scheduling happens instead of in the invoking middleware. Removed ScheduleBackgroundActivities.cs handler and added ScheduleBackgroundActivitiesMiddleware.cs instead. As a part of this change, restructured BackgroundActivityInvokerMiddleware to BackgroundActivityCollectorMiddleware, and updated all relevant references.
Minor modifications to a few other files include changes in their package dependencies and activity kind settings.
* Remove unused NOOP stores
* Add activity execution manager and FindAsync method to store
The notification is used to broadcast changes to SignalR clients.
* Refactor ActiveActivityExectionContexts
Instead, the workflow state extractor is in control of what gets extracted.
* Add missing files for activity execution deleted broadcast
* Update Flowchart to not fault when child faults
* Update Flowchart to support scheduling existing activity instances
* Update namespaces from Services to Stores
* Improve activity cancellation alteration
* Update ScheduleActivity alteration
* Implement Alteration types and engine
* Implement Alteration APIs
* Refactor activity work item with support for activity input
* Serialize scheduled activities as part of workflow state
* Add signal to schedule child activity
* Implement stores for plans and jobs
* Add EF Core provider
* Add Retry endpoint
* Keep root context as always active. The root context is the workflow execution context and contains persistent variable state
* Regenerate EF Core migrations
* Handle orphaned activity execution contexts
* Refactor workflow execution factory
* Enable configuring Jint from Program
* Update ModifyVariable alteration with support for type deserialization
* Use ShortGuid for identity
* Cleanup WorkflowServer host
