[Cosmos] Migrate get_document to pipelines architecture

[eholk]

This migrates get_document to the new pipelines architecture and updates all the examples to compile.

I'm sure this can be improved, so I'd definitely appreciate code review feedback. Also, although the examples compile, I didn't run them so I'm not 100% sure this preserves the previous behavior. Is there a standard approach people have to testing these things?

Issue #290

[rylev]

Thanks! Looks great. We don't have a good way of testing right now (that's in the works with #348) so we'll need to test this manually.

I only had one comment on some dead code we can remove.

Overall, I think it might make sense for us to merge this and then when #348 we can ensure it's in working order.

[JoshGendein]

Not sure what others are doing but I just created a cosmos account in a personal subscription and test manually. Also because the e2e tests are behind a feature don't forget to check them with cargo check --tests --features test_e2e. I think you can add this as config to rust-analyzer.

[eholk]

@JoshGendein - Thanks for the suggestion. I found some more code that needs to be updated by doing that. I'll try doing the e2e tests on a personal subscription too.

[eholk]

Okay, I tried running the tests on a personal subscription. I had failures on create_and_delete_document as well as replace_document, but I get similar failures on the main branch, so it doesn't seem like my change broke it.

[rylev]

♥ Thank you!