Add @NoParameters annotation for activity type classes

Checked for duplicates

Yes - I've already checked

Alternatives considered

No - I haven't considered

Related problems

I'm frustrated when I get a compile error when I don't annotate any actvity type class fields as @Export.Parameter.

For activity type definitions, I often have fields for the class that I don't annotate as @Parameter. If no fields are annotated as @Parameter, the annotation processor considers all fields as parameters, which is a nice feature, but in some cases I want no parameters even though I have fields. Often, I have fields for which I don't have mappers and don't care/want to expose them as parameters, so I get an compile error.

Describe the feature request

I want something like a @NoParameters annotation for the class to prevent it from automatically creating the parameters for all of the fields. I do like the default to be to create the Parameters automatically, so I don't want to change that, especially since it would be a breaking change.

Start by locating the Java annotation processor for activity type definitions and the handling of @Export.Parameter. Trace how it treats classes with no annotated fields, then define the desired @NoParameters behavior and verify that fields remain excluded from generated parameters when the annotation is present.