fix(MultiEdits): fire valueChanged when syncing form same fields

If not, mIsChanged state and multiedit button icon are not updated in
QgsAttributeFormEditorWidget. The former leads to not saving
modification issues when applying multi edit modifications because
widget could appear not changed.

src/gui/qgsattributeform.cpp

@@ -1010,9 +1010,8 @@ void QgsAttributeForm::onAttributeChanged( const QVariant &value, const QVariant
     if ( formEditorWidget->editorWidget() == eww )
       continue;
 
-    // formEditorWidget and eww points to the same field, so block signals
-    // as there is no need to handle valueChanged again for each duplicate
-    whileBlocking( formEditorWidget->editorWidget() )->setValue( value );
+    // formEditorWidget and eww points to the same field, so update its value
+    formEditorWidget->editorWidget()->setValue( value );
   }
 
   switch ( mMode )

tests/src/gui/testqgsdualview.cpp

@@ -438,11 +438,31 @@ void TestQgsDualView::testDuplicateField()
 
   const QList<QgsAttributeFormEditorWidget *> formEditorWidgets = dualView.mAttributeForm->mFormEditorWidgets.values( 0 );
 
+  // reset mIsChanged state
+  formEditorWidgets[0]->changesCommitted();
+  formEditorWidgets[1]->changesCommitted();
+  QVERIFY( !formEditorWidgets[0]->hasChanged() );
+  QVERIFY( !formEditorWidgets[1]->hasChanged() );
+
   formEditorWidgets[0]->editorWidget()->setValues( 20, QVariantList() );
+  QCOMPARE( formEditorWidgets[0]->editorWidget()->value().toInt(), 20 );
+  QCOMPARE( formEditorWidgets[1]->editorWidget()->value().toInt(), 20 );
+  QVERIFY( formEditorWidgets[0]->hasChanged() );
+  QVERIFY( formEditorWidgets[1]->hasChanged() );
   ft = layer->getFeature( ft.id() );
   QCOMPARE( ft.attribute( QStringLiteral( "col0" ) ).toInt(), 20 );
 
+  // reset mIsChanged state
+  formEditorWidgets[0]->changesCommitted();
+  formEditorWidgets[1]->changesCommitted();
+  QVERIFY( !formEditorWidgets[0]->hasChanged() );
+  QVERIFY( !formEditorWidgets[1]->hasChanged() );
+
   formEditorWidgets[1]->editorWidget()->setValues( 21, QVariantList() );
+  QCOMPARE( formEditorWidgets[0]->editorWidget()->value().toInt(), 21 );
+  QCOMPARE( formEditorWidgets[1]->editorWidget()->value().toInt(), 21 );
+  QVERIFY( formEditorWidgets[0]->hasChanged() );
+  QVERIFY( formEditorWidgets[1]->hasChanged() );
   ft = layer->getFeature( ft.id() );
   QCOMPARE( ft.attribute( QStringLiteral( "col0" ) ).toInt(), 21 );