As the Qt6 QString::QString(const QByteArray &ba) documenation says:
"Note: any null ('\0') bytes in the byte array will be included in this string, converted to Unicode null characters (U+0000). This behavior is different from Qt 5.x."
Make sure FieldInformation::toString() truncates its display label byte array before converting it to a QString.
Fixes #18428 (closed)
(cherry picked from commit f3f1556d)