Addresses CodeRabbit review on #3219, "Recognize the legacy Count
Numbers caption when the function changes": workbooks saved before
Count Numbers was captioned "Count of" carry "Count Numbers of Val"
(optionally with a number suffix). pivot.valueSettings now treats that
as an automatic caption of a Count Numbers field, so changing the
function renames it; a custom name stays.
Test: legacy_count_numbers_caption_follows_the_function.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
