EffectComposer: Fix slider value precision

Effects with slider controlled real values now properly cut the values
to two decimals.

Fixes: QDS-11773
Change-Id: I056a295e5a126536d3003490c938361e4ce382b3
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

share/qtcreator/qmldesigner/effectComposerQmlSources/ValueFloat.qml

@@ -42,8 +42,9 @@ Row {
         to: uniformMaxValue
         value: uniformValue
         onMoved: {
-            uniformValue = value
-            spinBox.value = value // binding isn't working for this property so update it
+            let fixedValue = Number.parseFloat(value).toFixed(slider.decimals)
+            uniformValue = fixedValue
+            spinBox.value = fixedValue // binding isn't working for this property so update it
         }
     }
 }