Consistent formatting for JSON type identifiers

[Whathecode]

@bardram observed the following:

Another question is - when do you use lower versus upper case - what is the difference between these two?

"attribute": {
"__type": "dk.cachet.carp.common.application.users.ParticipantAttribute.DefaultParticipantAttribute",
"inputDataType": "dk.cachet.carp.input.sex"
}
Why is sex lower case and DefaultParticipantAttribute upper case?

This is fairly arbitrary:

That's unfortunately something that leaks out from the implementation. The PascalCase types are types in the codebase using default polymorphic serialization, which just uses the namespace.ClassName. The lowercase types are data types, which are handled differently and registered manually, since they are so central to the framework. I think it would make sense that at least all extendable types (data, devices, tasks) adopt this lowercase style, but I see that is not the case atm (devices use PascalCase).

For consistency, it would make sense to align on common formatting for all CARP types. For backwards compatibility, this would need API migrations, however!