`@Function`, `@Field`, and `@Class` responses should include populated `location`

The `location` property for `@Function`, `@Field`, and `@Class` is technically marked as optional in the specification for legacy reasons, but should always be provided in order to allow for these objects to be associated with a parent script. Having location information also allows for us to determine where the code is in a script without having to request the full object.

This is blocking program explorer from working correctly with dwds.

Start by tracing how responses for @Function, @Field, and @Class are produced and how their location property is populated. Compare the implementation with the specification and check the DWDS program explorer behavior; done means each response includes location information sufficient to associate the object with its parent script and locate its code without requesting the full object.

Written by the indexing model from the issue text.