Read V1 ManifestList with V2 projection

[Fokko]

Is your feature request related to a problem or challenge?

It would be nice to directly project a V1 manifest as a V2 manifest.

To allow this, we need to set initial defaults for the fields that are required in V2:

Similar to #1482

Describe the solution you'd like

No response

Willingness to contribute

I cannot contribute to this feature at this time

[Kurtiscwright]

Hi Fokko, this seems pretty straight forward and the reference PR is helpful. I will try to get an initial PR shortly.

[Kurtiscwright]

Looking deeper into this, did the previous PR get Manifest and ManifestList mixed up? I believe the schema for Manifest live in crates/iceberg/src/spec/manifest/ which was updated in PR #1482 while the ManifestList schema seems to live at crates/iceberg/src/spec/manifest_list.rs

Example from manifest_list.rs

static CONTENT: Lazy<NestedFieldRef> = {
        Lazy::new(|| {
            Arc::new(NestedField::required(
                517,
                "content",
                Type::Primitive(PrimitiveType::Int),
            ))
        })
    };

I can work on updating either or both if something was missed, just want to double check my understanding first though.

[Fokko]

Looking deeper into this, did the previous PR get Manifest and ManifestList mixed up?

Yes, you're right. That was my mistake in #1471 that pointed to the manifest :) Looking forward to the PR!