GH-54533: [C++][Parquet] Avoid emitting empty data pages and advance past empty pages in reader - #54582

Rationale for this change

When writing a repeated column with a single record or a small data_page_size, the Parquet writer could evaluate page limits when num_buffered_values_ == 0. Because empty encoders (such as RleBooleanEncoder and dictionary encoders) return a small non-zero estimated size (e.g. 69 bytes or 6 bytes), EstimatedDataEncodedSize() >= data_pagesize() evaluated to true and AddDataPage() was invoked, writing an empty data page (num_values = 0, num_rows = 0) at the start of the column chunk.

On read, ColumnReaderImplBase::HasNextInternal() checked if (!ReadNewPage() || num_buffered_values_ == 0) and returned false, erroneously treating the empty data page as end-of-column-chunk and silently dropping all rows in that row group.

What changes are included in this PR?

1. Writer Fixes:
   • In TypedColumnWriterImpl::CommitWriteAndCheckPageLimit: required num_buffered_values_ > 0 before checking page limit conditions and triggering AddDataPage().
   • In ColumnWriterImpl::AddDataPage(): added an early-return guard if (num_buffered_values_ == 0) return; to prevent writing empty data pages.
2. Reader Fix:
   • In ColumnReaderImplBase::HasNextInternal(): converted the page check to a while (num_buffered_values_ == 0 || num_decoded_values_ == num_buffered_values_) loop so that any data page with zero values is skipped, advancing to subsequent pages rather than prematurely terminating read. This provides backward compatibility for existing Parquet files.
3. Tests:
   • Added unit tests in cpp/src/parquet/arrow/arrow_reader_writer_test.cc:
     • SingleRowRepeatedSmallPageSize: single-row repeated column with small data_page_size and V2 data pages.
     • LastRowGroupSingleRowRepeatedSmallPageSize: repeated columns across multiple row groups where the last row group has 1 row.
     • ListDictionarySmallPageSize: repeated columns with dictionary encoding and small page size.
     • MultiColumnRepeatedSmallPageSize: multi-column table with a repeated column.

Are these changes tested?

Yes, new unit tests covering repeated columns with small page sizes and dictionary encoding have been added to arrow_reader_writer_test.cc.

Are there any user-facing changes?

No breaking changes. This fixes a silent data loss bug where repeated columns with small page sizes or single-row batches had rows dropped.

This PR contains a "Critical Fix".
Fixes a bug that caused rows in Parquet files with repeated columns to be silently missing on read.

Was AI used for this PR?

PR code and description written by:

• AI

Reviewed before submission by:

• Human

Closes #54533.

• GitHub Issue: [C++][Parquet] Writer emits an empty first data page for a repeated column when data_page_size is small, and the reader then drops the row group's rows #54533