Include gituserchrome; Update ff ultima

[soulhotel]

I spent some time testing gituserchrome through vm's until I got consistent behavior on the 3 major platforms. Unfortunately, I can't make interaction with the FCSS store as good as a native webview, due to webkit restrictions with COR. Maybe with some iteration of postmessage to share clicked links with any potential parent idk. But I went ahead and included gituserchrome & updated some of ff ultima's information for this PR.

('click', (event) => {
    const link = event.target.closest('a');
    if (link && link.href) {
        window.parent.postMessage({
            type: 'clickedLink', href: link.href
        }, '*');
    }
});

[Neikon]

Merged, thank you for your work