Support reading initial-defaults

[Fokko]

No description provided.

[gabeiglio]

Since initial-default projection happens after filtering in _task_to_record_batches Im wondering if this will yield the correct results given a pyarrow_filter for this field.

[Fokko]

Since initial-default projection happens after filtering in _task_to_record_batches Im wondering if this will yield the correct results given a pyarrow_filter for this field.

Thanks for pointing this out, and it doesn't handle the filtering correctly. Let me work on a fix. Thanks!

[gabeiglio]

No problem! I was trying to get a test case for this by evolving the schema of a table and adding a new field with some initial-default value, but i think that have to wait for V3 table spec

[kevinjqliu]

@Fokko could you rebase this when you get a chance

[Fokko]

@kevinjqliu Sure, but I think this relies on #1770 to do some proper testing 👍