fdo#74441 [Accessiblity] Don't expose 0 for empty cells in Calc

At the moment non numercial cells in Calc is exposed to AT tools
(screen readers etc) as the value 0. It makes more sence to present
the string value of the cell which basically is what a sighted user
will see. This small patch should be a good start into making
Calc more accessible on Windows.

Change-Id: Ide76f2dc044c98f32aa78836049f12f2251522eb
Reviewed-on: https://gerrit.libreoffice.org/11996Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

winaccessibility/source/service/AccObject.cxx

@@ -390,6 +390,7 @@ void  AccObject::SetValue( Any pAny )
     case TEXT:
     case PARAGRAPH:
     case HEADING:
+    case TABLE_CELL:
 
         if(pRText.get())
         {
@@ -400,7 +401,6 @@ void  AccObject::SetValue( Any pAny )
     case TREE_ITEM:
     //case CHECK_BOX:   //Commented by Li Xing to disable the value for general checkbox
     case COMBO_BOX:
-    case TABLE_CELL:
     case NOTE:
     case SCROLL_BAR:
         m_pIMAcc->Put_XAccValue( GetMAccessibleValueFromAny(pAny).getStr() );