Enable enable_row_number_to_aggregate by default #24761

Is your feature request related to a problem or challenge?

In PR #23824, ReplaceFilterTop1 rewrites Filter(row_number() = 1) over a PARTITION BY window into Aggregate(first_value(...) GROUP BY partition). The rewrite is currently behind the config optimizer.enable_row_number_to_aggregate, which currently defaults to false - this was originally due to #23601 not being merged in yet, but as #23601 is now closed out it would be helpful for this to be enabled by default

Describe the solution you'd like

To flip enable_row_number_to_aggregate to true:

• Confirm nested/wide types no longer hit the per-group Accumulator path, and measure the remaining GenericValueState cost vs primitives.
• Benchmark Window+Filter vs the rewritten Aggregate across partition cardinality, payload width, and value types (primitive, string, nested)
• Confirm there are no remaining correctness gaps for the rewrite
• If results look good, set the default to true, drop the "disabled by default" note in config.rs, and regenerate docs/source/user-guide/configs.md plus information_schema.slt.

Describe alternatives you've considered

Keep off by default (wouldn't be very useful for optimization)

Additional context

See original issue: #23603 & original PR: #23824 & associated epic: #23600