Also set documentNode context in CookieSettingsPage.fusion

[patricekaufmann]

Homepage rendering that relies on documentNode context fails when being rendered in backend since the context is not correct.

Suggestion:

    renderer = Neos.Fusion:Renderer {
        type = ${site.nodeType.name}
        @context.node = ${site}
        @context.documentNode = ${site}

        @process.addCookieSettings = ${String.pregReplace(value, '/(.*)<\/body>(.*)/s', '$1' + cookieSettings + "</body>$2")}
    }