Expands the Symbolic Macros tests.

[thomasvl]

• Test overriding attribute docs
• Test blocking an inherited attribute remove it from the docs.
• Make the doc values distinct to make it clear where values come from.
• Add uses of inherit_attrs where the macro doesn't have a doc value.

[thomasvl]

All the test pass locally, and the failing tests don't seem related since I didn't change any files used in those tests.