This commit adds validation for cron expressions in the DefaultTriggerScheduler class. The system now checks if the cron expression provided is empty and issues a warning if that's the case. This prevents attempts to schedule triggers with an empty cron expression, which would fail.
The `DefaultTriggerScheduler` received a significant refactoring, with the injection of the `ISystemClock` service and a modification of several method calls. Additionally, a check is included to avoid scheduling `StartAt` triggers if their execution time is in the past. For these triggers, an information message is logged and scheduling is skipped.
* Initial implementation of workflow inbox, submission and delivery
* Implement persistence providers
* Update EF Core migrations
* Rename Services to Stores in Dapper module
* Use default serializer for primitive arrays
* Update MongoDB provider to map BookmarkId to be primary key
* Implement MongoDB provider for activity execution logs
* Use EF Core by default
* Fix private JSON constructor logic
* Incremental work on WorkflowStateSerializer
* Update Flow HTTP Request activity to default to Done outcome
* Fix reference handling
* Fix polymorphic object converter
* Add comments
* Add support for registering type alias during DI setup via options
* Fix trigger and bookmark payload persistence
* Update sample model
* Add support for custom dictionary types
* Split general serializer options provider into focused serializer services
* Formatting
* Update migrations
