* Initial working grain
* Incremental work on actor bookmark management & resuming wokflows
* Upgrade Proto Actor package references
* Fix lifetime of actors
* Implement bookmark and resumption
* Update Program.cs
* Update bookmark event publishing
* Refactor proto actor features API
* Implement snapshotting
* Update snapshotting
* Add in-memory provider and use it by default
* Update server bundle to use proto actor sqlite persistence by default
* Incremental work on custom activities
* Incremental work on refactoring versioned entities
* Add ActivityDefinition infrastructure
* Incremental work on activity definition manager
* Incremental work on API endpoints
* Refactored flowchart component to include hierarchical nav
* Incremental work on modularization of designer component
* Restructuring into modules
* Rename CustomActivities module
* Apply security
* Fix activity definition GET endpoint
* Incremental work on activity definition provider
* Incremental work on activity definition execution
* Update ActivityDefinitionMaterializer.cs
* Update ActivityDefinitionActivityProvider.cs
* Add activity definition referenced version update handler
* Maintain position of not found activity
* Fix prefix naming