Track extension enums

[groner]

This PR fixes a crash when inspecting tables or types referencing enums that belong to an extension.

I haven't figured out how to make the postgresql extension available for the test in circleci. It doesn't seem like there's a way to add files to the auxiliary containers, so I guess we need to build a new image with it included.

[groner]

This is kind of a breaking change, because existing versions of migra won't know to exclude enums with is_extension set. This could be avoided by exposing extension enums separately.

@djrobstep What are your thoughts on this?

[djrobstep]

Yep I think to work around this, we ought not to have enums from extensions included in the enum list. Perhaps a good solution is a separate dict of extension_enums.

That way it won't cause breaking changes. But then during dependency tracking that dict can also be looked in for dependencies. What do you think?

[groner]

Adding extension_enums sounds good to me.

[groner]

@djrobstep I wasn't sure if extension_enums should be used in PostgreSQL.dependency_order and I couldn't find any uses of it outside of the tests.

[jaredramirez]

@djrobstep I'm hitting this issue in my database. Do you know the status of this PR?

[sweatybridge]

Hi @djrobstep, I'm hoping to get a status update on this PR as well.

For your context, we recently added migra as an experimental diff tool to Supabase CLI and encountered the same issue with enum. As a temporary workaround, we are monkey patching this library here.