### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/main/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/main/CODE_OF_CONDUCT.md) that this project adheres to.
- [X] I have searched the [issue tracker](https://www.github.com/electron/electron/issues) for a bug report that matches the one I want to file, without success.

### Electron Version

18.0.4

### What operating system are you using?

Ubuntu

### Operating System Version

Ubuntu 20.0.4

### What arch are you using?

x64

### Last Known Working Electron version

_No response_

### Expected Behavior

File Selection Dialog should show files with the filtered extension, with no need for case match.

### Example:

`*.Foo` files should show up if we set filters for `[{name: 'Foo Files', extensions: ['Foo']}]` or even ``[{name: 'Foo Files', extensions: ['foo']}]`.

### Actual Behavior

File Selection Dialog does not show any files if the Filter contains a mixed case extension string.

### Example:

`*.Foo` files do not show up if we set filters for `[{name: 'Foo Files', extensions: ['Foo']}]` or even ``[{name: 'Foo Files', extensions: ['foo']}]` and any case match setup.

### Testcase Gist URL

https://gist.github.com/047baebf59014c18491c4efdfb75a5f8

### Additional Information

The issue probably come from this [function](https://github.com/electron/electron/blob/main/shell/browser/ui/file_dialog_gtk.cc#L250-L266)  (https://github.com/electron/electron/blob/main/shell/browser/ui/file_dialog_gtk.cc#L250-L266)  that seems to only check for lowercased or uppercased extensions. 

### Example:

`[{name: 'Foo Files', extensions: ['Foo']}]` will only show `*.foo` or `*.FOO` files.

### Gist
In the provided gist, it will ask you to add a `aim-file.Js` file. Please add it. Then run the fiddle. It will open a File Selection Dialog and will not show the `aim-file.Js`. If you change the file type to `All`, that file will show up.
shell/browser/ui/file_dialog_gtk.cc
}
        gtk_file_chooser_set_current_name(
            GTK_FILE_CHOOSER(dialog_),
            settings.default_path.BaseName().value().c_str());
      }
    }
    if (!settings.filters.empty())
      AddFilters(settings.filters);
    
    
    
    
    if (!electron::IsElectron_gtkInitialized()) {
      preview_ = gtk_image_new();
      g_signal_connect(dialog_, "update-preview",
                       G_CALLBACK(OnUpdatePreviewThunk), this);
      gtk_file_chooser_set_preview_widget(dialog_, preview_);
    }
  }
  ~FileChooserDialog() {
    if (electron::IsElectron_gtkInitialized()) {
      gtk_native_dialog_destroy(GTK_NATIVE_DIALOG(dialog_));
    } else {
      gtk_widget_destroy(GTK_WIDGET(dialog_));
    }
    if (parent_)
      parent_->SetEnabled(true);
  }
  
  FileChooserDialog(const FileChooserDialog&) = delete;