Adjust macOS Tray/Menu icons scaling (#19628)

* Set TrayIcon image size to 17, 17

* Use Floor for setting icon size

native/Avalonia.Native/src/OSX/menu.mm

@@ -262,10 +262,10 @@ HRESULT AvnAppMenuItem::SetIcon(void *data, size_t length)
             NSSize originalSize = [image size];
              
             NSSize size;
-            size.height = [[NSFont menuFontOfSize:0] pointSize] * 1.333333;
+            size.height = floor([[NSFont menuFontOfSize:0] pointSize] * 1.333333);
             
             auto scaleFactor = size.height / originalSize.height;
-            size.width = originalSize.width * scaleFactor;
+            size.width = floor(originalSize.width * scaleFactor);
             
             [image setSize: size];
             [_native setImage:image];

native/Avalonia.Native/src/OSX/trayicon.mm

@@ -39,10 +39,10 @@ HRESULT AvnTrayIcon::SetIcon (void* data, size_t length)
             NSSize originalSize = [image size];
              
             NSSize size;
-            size.height = [[NSFont menuFontOfSize:0] pointSize] * 1.333333;
-            
+            size.height = floor([[NSFont menuFontOfSize:0] pointSize] * 1.333333);
+
             auto scaleFactor = size.height / originalSize.height;
-            size.width = originalSize.width * scaleFactor;
+            size.width = floor(originalSize.width * scaleFactor);
             
             [image setSize: size];
             [image setTemplate: _isTemplateIcon];