feat: Include statistics for Reserved Fields

[Fokko]

This is a behavioral change.

In Iceberg-Rust we require upper/lower bounds to be part of the schema. But in some cases, this isn't the case, for example when you use reserved fields. In PyIceberg we expect these values in some tests:

FAILED tests/integration/test_inspect_table.py::test_inspect_files[2] - AssertionError: Difference in column lower_bounds: {} != {2147483546: b's3://warehouse/default/table_metadata_files/data/00000-0-8d621c18-079b-4217-afd8-559ce216e875.parquet', 2147483545: b'\x00\x00\x00\x00\x00\x00\x00\x00'}
assert {} == {2147483545: ...e875.parquet'}
  Right contains 2 more items:
  {2147483545: b'\x00\x00\x00\x00\x00\x00\x00\x00',
   2147483546: b's3://warehouse/default/table_metadata_files/data/00000-0-8d621c1'
               b'8-079b-4217-afd8-559ce216e875.parquet'}
  Full diff:
    {
  +  ,
  -  2147483545: b'\x00\x00\x00\x00\x00\x00\x00\x00',
  -  2147483546: b's3://warehouse/default/table_metadata_files/data/00000-0-8d621c1'
  -              b'8-079b-4217-afd8-559ce216e875.parquet',
    }
!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!
==== 1 failed, 238 passed, 32 skipped, 3123 deselected in 61.56s (0:01:01) =====

This is a positional delete where the field-IDs are constant, but never part of a schema (they are reserved).

Which issue does this PR close?

• Closes #.

What changes are included in this PR?

Are these changes tested?

[kevinjqliu]

LGTM! This aligns with both pyiceberg and spark behavior

[kevinjqliu]

manually retriggering ci runs, due to #1838 😞

[kevinjqliu]

LGTM!!

should we update the PR title/description to reflect the new changes?

[kevinjqliu]

nit: add _partition here for completeness?

[Fokko]

Added 👍

[kevinjqliu]

nit: add row for completeness?

[Fokko]

I left out row on purpose, since it is a struct that corresponds with the table schema. row can be used to decide if a positional delete is relevant for your query (since you collect statistics for the rows that are dropped), but I don't think any engine leverages that today. There was even a thread on the dev-list to deprecate this functionality.

[kevinjqliu]

LGTM!

looks like the ci is stuck, i retriggered it

[liurenjie1024]

Thanks @Fokko , LGTM!

[Fokko]

Thanks @kevinjqliu and @liurenjie1024 for checking 🙌