Fix limited statistic collection accross files with no stats

[isidentical]

Which issue does this PR close?

Closes #4323.

Rationale for this change

Even in the cases where none of the files included stats/byte size information, get_statistics_with_limit was generating statistics with the claims of zero rows / zero bytes. This PR fixes it to only include the number of rows when it is known.

What changes are included in this PR?

For preserving the old relaxed behavior, this PR changes the collection to include row/byte count information when any of them are present in any of the files. If it is only present in even one file, that is enough for the listing (all the others are counted towards zero rows, which is the existing behavior).

Are these changes tested?

Yes.

Are there any user-facing changes?

No.

[alamb]

LGTM -- thank you @isidentical

[alamb]

👍

[alamb]

If you are into a more functional style of coding, you can do something like the following as well

Suggested change

	num_rows = if let Some(num_rows) = num_rows {
	Some(num_rows + file_stats.num_rows.unwrap_or(0))
	} else {
	file_stats.num_rows
	};
	total_byte_size = if let Some(total_byte_size) = total_byte_size {
	Some(total_byte_size + file_stats.total_byte_size.unwrap_or(0))
	} else {
	file_stats.total_byte_size
	};
	num_rows = num_rows
	.map(|num_rows| num_rows + file_stats.num_rows.unwrap_or(0))
	.or(file_stats.num_rows);
	total_byte_size = total_byte_size
	.map(|total_byte_size| total_byte_size + file_stats.total_byte_size.unwrap_or(0))
	.or(file_stats.total_byte_size);

[alamb]

cc @mingmwang

[ursabot]

Benchmark runs are scheduled for baseline = 8d36529 and contender = 067d044. 067d044 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-thinkcentre-m75q] ursa-thinkcentre-m75q
Buildkite builds:
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java