Fix QSqlQuery copy and Qt6 deprecation issues

- Suppress deprecated QSqlQuery copy-constructor warning locally in NSqlQuery::operator=
- Replace qChecksum overload with QByteArrayView
- Use QTimeZone::utc(), QLibraryInfo::path(), check QTranslator::load return values
- Replace deprecated operator+ for key combinations and other small Qt6 fixes

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Z/src/qsql_informix/qsql_informix.cpp

@@ -24,6 +24,7 @@
 #include <QTextCodec>
 #include <QTimer>
 #include <QVariant>
+#include <QMetaType>
 
 
 
@@ -726,7 +727,7 @@ QSqlRecord QInformixResult::record() const
     f.setType(qSqlType2Variant(sqlType));
     f.setSqlType(sqlType);
 
-    if (f.type() == QVariant::Invalid)
+    if (qSqlType2Variant(sqlType) == QVariant::Invalid)
       qWarning("QInformixResult::record(): Unknown datatype %s", typeName);
 
     info.append(f);
@@ -806,7 +807,7 @@ bool bindValues(T *prep, const QVector<QVariant> &boundValues, const QInformixRe
     const QVariant &val = boundValues.at(i);
     ITValue *param = prep->Param(i);
 
-    if (val.type() == QVariant::ByteArray)
+    if (val.metaType().id() == QMetaType::QByteArray)
     {
       ITDatum *lobj;
 
@@ -870,7 +871,7 @@ bool bindValues(T *prep, const QVector<QVariant> &boundValues, const QInformixRe
       }
       else
       {
-        f.setType(val.type());
+        // setValue() already sets the type appropriately
         f.setValue(val);
         if (!param->FromPrintable(p->driverPrivate->toInformixEncoding(driver->formatValue(f))))
           return false;