<!--  As an open source project with a dedicated but small maintainer team, it can sometimes take a long time for issues to be addressed so please be patient and we will get back to you as soon as we can.
-->

### Preflight Checklist
<!-- Please ensure you've completed the following steps by replacing [ ] with [x]-->

* [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
* [x] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
* [x] I have searched the issue tracker for a feature request that matches the one I want to file, without success.

### Problem Description
<!-- Is your feature request related to a problem? Please add a clear and concise description of what the problem is. -->

They is no way to choose the paper format (A4, A3, Letter, ...) when printing with `webContents.print()`.

### Proposed Solution
<!-- Describe the solution you'd like in a clear and concise manner -->

Add something like the `pageSize` option which is available in [`webContents.printToPDF()`](https://electronjs.org/docs/api/web-contents#contentsprinttopdfoptions-callback).

shell/browser/api/electron_api_web_contents.cc
#if defined(OS_MACOSX)
  base::ScopedCFTypeRef<CFStringRef> new_printer_id(
      base::SysUTF16ToCFStringRef(device_name));
  PMPrinter new_printer = PMPrinterCreateFromPrinterID(new_printer_id.get());
  bool printer_exists = new_printer != nullptr;
  PMRelease(new_printer);
  return printer_exists;
#elif defined(OS_WIN)
  printing::ScopedPrinterHandle printer;
  return printer.OpenPrinterWithName(device_name.c_str());
#endif
  return true;
}
base::string16 GetDefaultPrinterAsync() {