useContentHead should add og:image including base url.

[madebyfabian]

Is your feature request related to a problem? Please describe

Currently, useContentHead just adds the relative path to the image as the og:image. This is invalid though. See

• Open Graph "og:image" attribute should use absolute URL instead of relative jitsi/jitsi-meet#6031

Describe the solution you'd like

Either use some globally defined option defined in the nuxt.config.ts (preferred one), or add it as an option to define the base url when using useContentHead.

Describe alternatives you've considered

useContentHead(page.value)

useSeoMeta({
  ogImage: page.value.image?.src ? joinURL(runtimeConfig.public.siteUrl, page.value.image.src) : undefined,
})