Ensure dialogs are visible on all Spaces

We never want to hide dialogs if their parent is on a different Space
(MacOS-specific terminology), so set the window property to show
everywhere when showing a dialog

Fixes https://gitlab.com/kicad/code/kicad/-/issues/13906

common/dialog_shim.cpp

@@ -302,6 +302,8 @@ bool DIALOG_SHIM::Show( bool show )
 
         m_userPositioned = false;
         m_userResized = false;
+
+        KIPLATFORM::UI::EnsureVisible( this );
     }
     else
     {

libs/kiplatform/include/kiplatform/ui.h

@@ -183,6 +183,14 @@ namespace KIPLATFORM
          */
         void InfiniteDragReleaseWindow();
 
+        /**
+         * Ensure that a window is visible on the screen.  On MacOS, this will make it visible
+         * in all Spaces.  Other platforms are nops.
+         *
+         * @param aWindow window to make visible
+         */
+        void EnsureVisible( wxWindow* aWindow );
+
         /**
          * Intended to set the floating window level in macOS on a window
          */

libs/kiplatform/port/wxgtk/ui.cpp

@@ -142,6 +142,12 @@ bool KIPLATFORM::UI::IsWindowActive( wxWindow* aWindow )
 }
 
 
+void KIPLATFORM::UI::EnsureVisible( wxWindow* aWindow )
+{
+    // Not needed on this platform
+}
+
+
 void KIPLATFORM::UI::ReparentModal( wxNonOwnedWindow* aWindow )
 {
     // Not needed on this platform

libs/kiplatform/port/wxmsw/ui.cpp

@@ -76,6 +76,12 @@ bool KIPLATFORM::UI::IsWindowActive( wxWindow* aWindow )
 }
 
 
+void KIPLATFORM::UI::EnsureVisible( wxWindow* aWindow )
+{
+    // Not needed on this platform
+}
+
+
 void KIPLATFORM::UI::ReparentModal( wxNonOwnedWindow* aWindow )
 {
     // Not needed on this platform

libs/kiplatform/port/wxosx/ui.mm

@@ -88,6 +88,21 @@ bool KIPLATFORM::UI::IsWindowActive( wxWindow* aWindow )
 }
 
 
+void KIPLATFORM::UI::EnsureVisible( wxWindow* aWindow )
+{
+    NSView* view = (NSView*)aDialog->GetHandle();
+    if( view )
+    {
+        NSWindow* nsWindow = [view window];
+        if( nsWindow )
+        {
+            [nsWindow setCollectionBehavior:
+                NSWindowCollectionBehaviorCanJoinAllSpaces];
+        }
+    }
+}
+
+
 void KIPLATFORM::UI::ReparentModal( wxNonOwnedWindow* aWindow )
 {
     wxTopLevelWindow* parent =