clean up metadata, typemeta + listmeta + apistatus + apierror

[clux]

Should have those structs fully in the library, and should probably flatten typemeta into Object.
ObjectList should get a ListMeta rather than ObjectMeta (rename), ApiStatus (rename to Status), should have ListMeta (ref) - probably also join ApiStatus and ApiError (same underlying object)

Ultimately small cleanups, but helps keep things consistent.

[clux]

Might not do the flattening and just have the explicit fields.. It's a bit annoying to have to type:

• o.typemeta.kind rather than o.kind
• o.typemeta.version rather than o.version

[clux]

Added listmeta and renamed status in c14ef96

Now whether or not to re-export ApiError as Status 🤔