bench(parquet): add row filter strategy baseline cases

[hhhizzz]

Which issue does this PR close?

• Part of [Parquet] Better heuristics to pick between RowSelection and Mask filter representation #8846.
• Part of [EPIC] Faster performance for parquet predicate evaluation for non selective filters #7456.
• Split out from Optimize parquet row filter auto strategy with adaptive fallback #9956.

Rationale for this change

This PR is the first smaller PR split out from #9956 ("Optimize parquet row filter auto strategy with adaptive fallback").

The goal is to land the benchmark coverage first, before changing row-filter planning or execution behavior. This gives follow-up PRs a stable benchmark baseline already on main, making it easier to compare each later behavior change against the same benchmark cases.

Planned split from #9956:

1. Add benchmark baseline cases. This PR.
2. Split row-selection strategy / sparse mask correctness changes.
3. Add post-filter execution primitives.
4. Add Auto policy / adaptive materialization core.
5. Add policy refinements for projected predicates, fixed-prefix guards, and cacheable predicate cases.

What changes are included in this PR?

This PR adds benchmark coverage only. The diff is limited to benchmark targets under parquet/benches, with no changes to production reader code or public APIs.

It extends arrow_reader_row_filter with:

• strategy comparison cases for:
  • manual full-scan post-filtering;
  • current RowSelectionPolicy::Auto;
  • explicit Selectors;
  • explicit Mask;
• focused row-filter shapes inspired by ClickBench and TPC-DS workloads;
• projected-predicate cases;
• count-only / filter-only / fixed-width / variable-width projection cases;
• nested whole-root output benchmark coverage;
• projected scan focus cases that do not construct a RowFilter.

It also extends row_selection_cursor with shape-focused selector/mask cases that vary:

• selected-run length;
• selectivity;
• primitive vs variable-width payloads.

This PR intentionally does not change production reader behavior.

Are these changes tested?

Yes. This PR was validated with:

cargo fmt -- parquet/benches/arrow_reader_row_filter.rs parquet/benches/row_selection_cursor.rs
cargo check -p parquet --bench row_selection_cursor --features arrow
cargo check -p parquet --bench arrow_reader_row_filter --features arrow,async
git diff --check

No benchmark result is claimed in this PR. The purpose is to add baseline benchmark coverage so later PRs can report comparable performance evidence.

Are there any user-facing changes?

No. This only changes benchmark code.