Add support for a null-safe filter operator ?|

My twig templates are full of code where I have a parameter, usually a date, that I need to display if it exists:

{{ site.startDate ? site.startDate|date('m/d/Y') }}

It would be nice if this could be shortened to something like this:

{{ site.startDate ?| date('m/d/Y') }}

I know that I could just write a a custom date filter that handles null input, along the lines of below, but this seems a bit much:

#[AsTwigFilter(name: 'safe_date', needsEnvironment: true)]
    public function safeDate(Environment $env, $date, ?string $format = null, $timezone = null): string
    {
        if (empty($date)) {
            return '';
        }
        return $env->getExtension(CoreExtension::class)->formatDate($date, $format, $timezone);
    }

No file, test, or entry point is named in the issue. Start by locating Twig's expression and filter syntax handling, then define and test the proposed null-safe ?| behavior using the examples; done means null values are handled as requested without breaking existing filter syntax.