wxwidgets.cfg: Added support for more missing interfaces. (danmar#8088)

This pull request updates the `cfg/wxwidgets.cfg` file to improve
coverage and accuracy of function definitions for wxWidgets classes. The
most important changes include adding new function definitions and
extending existing ones to cover additional classes and methods.

### Expanded function coverage

* Added a new function definition for `wxULongLong::GetValue`, allowing
retrieval of the value stored in a `wxULongLong` object.
* Updated the function definition for `Refresh` to include both
`wxWindow` and `wxPropertyGridManager`, ensuring correct handling of the
method for both classes.
* Extended the `IsOk` function definition to include `wxIcon`, in
addition to `wxColour` and `wxFont`, improving consistency across
related classes.…fresh' and 'wxIcon::IsOk'

Author: orbitcowboy

cfg/wxwidgets.cfg

@@ -10361,6 +10361,14 @@
     <const/>
     <use-retval/>
   </function>
+  <!-- wxULongLong_t wxULongLong::GetValue() const  -->
+  <function name="wxULongLong::GetValue">
+    <noreturn>false</noreturn>
+    <returnValue type="wxULongLong_t"/>
+    <leak-ignore/>
+    <const/>
+    <use-retval/>
+  </function>
   <!-- void * wxVariant::GetVoidPtr() const -->
   <function name="wxVariant::GetVoidPtr">
     <noreturn>false</noreturn>
@@ -12518,7 +12526,8 @@
     </arg>
   </function>
   <!-- virtual void wxWindow::Refresh(bool eraseBackground = true, const wxRect * rect = NULL) -->
-  <function name="wxWindow::Refresh">
+  <!-- virtual void wxPropertyGridManager::Refresh(bool eraseBackground = true, const wxRect * rect = NULL) -->
+  <function name="wxWindow::Refresh,wxPropertyGridManager::Refresh">
     <leak-ignore/>
     <noreturn>false</noreturn>
     <returnValue type="void"/>
@@ -15822,7 +15831,8 @@ wxItemKind kind = wxITEM_NORMAL) -->
   </function>
   <!-- bool wxColour::IsOk( void ) const -->
   <!-- bool wxFont::IsOk( void ) const -->
-  <function name="wxColour::IsOk,wxFont::IsOk">
+  <!-- bool wxIcon::IsOk( void ) const -->
+  <function name="wxColour::IsOk,wxFont::IsOk,wxIcon::IsOk">
       <noreturn>false</noreturn>
       <leak-ignore/>
       <returnValue type="bool"/>