Rationalize features that are in parquet-format but don't have entry on implementation status

While working on https://github.com/apache/parquet-site/pull/189 @emkornfield noticed there are several features that are in parquet-format but don't have entry on implementation status: https://github.com/apache/parquet-site/pull/189/changes#r3470611445

> Honestly I think most of these are so old, that it doesn't necessary add value, other then maybe providing a note on that page? Is there anything worth surfacing?

Looking more closely, these seem to be the modern ones:
* logical-variant-shredding - should be covered under variant type support? But maybe called out separately
* format-geospatial-statistics - should be covered under geospatial support? But maybe called out separately
* format-binary-protocol-extensions - Not clear if this is actually something on its own without a defined footer we want to use?
* format-ieee-754-total-order-and-nan-counts - This should be added (and we would ideally add a 2026 feature column for read support).

_Originally posted by @emkornfield in https://github.com/apache/parquet-site/issues/189#issuecomment-4812262300_

Start by reviewing the implementation-status page changes in parquet-site pull request 189 and compare them with the modern features listed here: logical-variant-shredding, format-geospatial-statistics, format-binary-protocol-extensions, and format-ieee-754-total-order-and-nan-counts. Done means deciding which features warrant entries or notes and adding the agreed IEEE 754 entry, including the proposed 2026 read-support column if confirmed.

Written by the indexing model from the issue text.