Cluttered autodoc output

[duckontheweb]

The autodoc output can be a bit cluttered and hard to make sense of in some cases. This is especially evident in function/method signatures that use other PySTAC classes as types, and when showing class inheritance, because the fully qualified path is used. The EOExtension class documentation is a good example of this: the Bases are more verbose than they need to be, and the type annotations in apply and ext are a little hard to make sense of at first.

We might be able to take advantage of the autodoc-process-signature event to clean up function signatures. When Sphinx 4.1 is released, we may also be able to take advantage of autodoc-process-bases to clean up the Bases section.