CGrid reviewDataWarningForGrid does not work with reverse show

[openlowcode]

CGrid needs to take into account the component being used. It does not do that today, and as a result, when using reverse show:

• there is an exception (see below)
• the warning may show in inappropriate times.

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
        at org.openlowcode.client.graphic.widget.CGrid.reviewDataWarningForGrid(CGrid.java:1235)
        at org.openlowcode.client.graphic.widget.CGrid.forceUpdateData(CGrid.java:1111)
        at org.openlowcode.client.graphic.CPageData$1.run(CPageData.java:122)
        at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)
        at java.security.AccessController.doPrivileged(Native Method)
        at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)
        at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
        at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at com.sun.glass.ui.win.WinApplication.lambda$null$3(WinApplication.java:177)