This commit refactors how expression descriptors are created and retrieved across Elsa project. The asynchronous methods have been simplified to synchronous ones removing unnecessary `ValueTask` returns. Additionally, `IExpressionDescriptorRegistryPopulator` has been removed resulting in less complexity and better performance.
* Incremental work
* Enable control over when to include full compositie root
* Cleanup
* Update WorkflowDefinitionActivity
* Implement input as variables
* Delete unused class
* Remove less common types
* Rename ExpandoObject to JSON
* Implement variable scoping
* Remove parent/child relationship from MemoryRegister
* Add support for sending input to "trigger event" endpoint
* Add support for configuring input storage driver
* Remove unused namespace imports
* Auto-register activity types when running a workflow
* Fix missing variables from containers