QmlDesigner: Allow area light dimensions larger than 100

There is no reason to cap area light dimensions to the default 100.

Change-Id: I07a3c933c2209182defa51aea690b640c6a66cc5
Fixes: QDS-1914
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/imports/quick3d/designer/AreaLightSection.qml

@@ -73,7 +73,8 @@ Column {
             SecondColumnLayout {
                 SpinBox {
                     minimumValue: 0
-                    maximumValue: 100
+                    maximumValue: 9999999
+                    realDragRange: 5000
                     decimals: 0
                     backendValue: backendValues.width
                     Layout.fillWidth: true
@@ -87,7 +88,8 @@ Column {
             SecondColumnLayout {
                 SpinBox {
                     minimumValue: 0
-                    maximumValue: 100
+                    maximumValue: 9999999
+                    realDragRange: 5000
                     decimals: 0
                     backendValue: backendValues.height
                     Layout.fillWidth: true