Support optional Parquet page index writes

## Feature Request / Improvement

PyIceberg doesn't expose Parquet page index writing, even though PyArrow supports it with `ParquetWriter(write_page_index=True)`.

### Use case / motivation

Page indexes let readers such as ClickHouse skip non-matching pages during predicate evaluation, avoiding decoding work for selective queries. Tables written by PyIceberg currently lack these indexes, so page-level pruning is not possible regardless of reader support.

### Proposed change

Add an opt-in `write.parquet.page-index-enabled` table property, default false, to preserve current output and file sizes. When enabled, PyIceberg passes `write_page_index=True` to PyArrow's ParquetWriter.

### Implementation

PR #3829 adds the table property, threads it through `_get_parquet_writer_kwargs`, documents it in mkdocs/docs/configuration.md, and includes unit and integration test coverage.

### Tooling note

I developed this with assistance from DS v4 Pro and reviewed the changes myself.

### References

- #3829

Beginne mit der Prüfung von PR #3829 und untersuche anschließend _get_parquet_writer_kwargs, mkdocs/docs/configuration.md sowie die genannten Unit- und Integrationstests. Als erledigt gilt die Änderung, wenn die Opt-in-Eigenschaft standardmäßig weiterhin false ist, bei true das Schreiben des PyArrow-Seitenindex aktiviert und die dokumentierten Tests erfolgreich sind.

Vom Indexierungsmodell aus dem Issue-Text verfasst.