QLocale::system() was not making use of QLocaleFormat::Narrow, always
treating it in the same way as QLocaleFormat::Short.
This patch fixes the issue for day and month names.
The implementation falls back to CLDR if system locale fails to
provide some data.
Pick-to: 6.2
Task-number: QTBUG-84877
Change-Id: Ia37e59dbf02d7a5e230f2767d294b9ab7de37f33
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
61343b5a3f