### 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
if (!electron::IsElectron_gtkInitialized()) {
    gtk_widget_show_all(GTK_WIDGET(dialog.dialog()));
  }
}
int RunFileDialog(const FileChooserDialog& dialog) {
  int response = 0;
  if (electron::IsElectron_gtkInitialized()) {
    response = gtk_native_dialog_run(GTK_NATIVE_DIALOG(dialog.dialog()));
  } else {
    response = gtk_dialog_run(GTK_DIALOG(dialog.dialog()));
  }
  return response;
}
bool ShowOpenDialogSync(const DialogSettings& settings,
                        std::vector<base::FilePath>* paths) {
  GtkFileChooserAction action = GTK_FILE_CHOOSER_ACTION_OPEN;
  if (settings.properties & OPEN_DIALOG_OPEN_DIRECTORY)
    action = GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER;
  FileChooserDialog open_dialog(action, settings);
  open_dialog.SetupOpenProperties(settings.properties);
  ShowFileDialog(open_dialog);
  const int response = RunFileDialog(open_dialog);
  if (response == GTK_RESPONSE_ACCEPT) {
    *paths = open_dialog.GetFileNames();
    return true;
  }
  return false;
}
void ShowOpenDialog(const DialogSettings& settings,