It was previously possible to select an input-only converter for
output or an output-only converter for input. Also add a comment to
explain why failure to probe for the auto output converter isn't an
error, where failure to probe for the auto input converter is.
Pick-to: 6.5
Task-number: QTBUG-111228
Change-Id: I17dfbbee7d8b5a9629e66d0e1a6a4014b01a7262
Reviewed-by: Ievgenii Meshcheriakov <ievgenii.meshcheriakov@qt.io>
(cherry picked from commit ccd59b2d4f8f1c4fde3f1498d28c0dc91ba75efd)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
b4e09800bb