Enable parquet filter pushdown (`filter_pushdown`) by default

In https://github.com/apache/arrow-datafusion/pull/3380 @thinkharderdev added support for evaluating filters during the parquet scan via the RowIndex mechanism 🎉

This feature is currently enabled via a feature flag, which is disabled by default.

This ticket tracks enabling this feature by default.

Currently known items are:
- [x] https://github.com/apache/arrow-datafusion/issues/3457
- [x] Review of parquet test coverage and add additional coverage as needed: https://github.com/apache/arrow-datafusion/pull/3976
- [x] https://github.com/apache/arrow-datafusion/issues/4005
- [x] https://github.com/apache/arrow-datafusion/issues/4006
- [x] https://github.com/apache/arrow-datafusion/issues/4046
- [ ] Enable this feature by default: https://github.com/apache/arrow-datafusion/pull/3828

Inizia esaminando PR 3828 e le issue prerequisito completate elencate nel ticket, in particolare il lavoro sulla copertura dei test parquet in PR 3976. Abilita filter_pushdown per impostazione predefinita, quindi verifica la copertura dei test parquet esistente e conferma che la funzionalità non richiede più un flag di opt-in.

Scritto dal modello di indicizzazione a partire dal testo della issue.