Add possibility to use dynamically loaded assemblies

[truthz03]

Because I need a way to load assemblies dynamically (plugins) in my project, I found some problems while serializing/deserializing payloads.
In order to solve this problem, I would like to implement a mechanism to resolve the necessary types manually if needed.

---

This change is 

[truthz03]

@dotnet-policy-service agree

[cvijayak]

@truthz03

Please confirm whether the commit "367f574" will resolve the bug "#5356"

[truthz03]

@cvijayak
No, my commit will not fix this bug. My commit gives the possibility to deserialize stored things into unknown objects.
This means, if I add some activities and there payloads as plugin (within a different AppDomain), it will be possible to deserialize the json content to a type only known by the plugin AppDomain.

The bug #5356 shows problems with the serialization. It throws an error because the type is System.Type, which is a known type. I also don't know why System.Type is not serializeable.

[truthz03]

Is there something to do for my to get the "SonarCloud Code Analysis" ready?
Or have I still to wait?

[sfmskywalker]

@truthz03 Thanks for your PR! At this point there's nothing for you to do, I just need time to review and test. Thank you for your patience.