Add content hash for dynamic og image routes (#47440)
* Add `contenthash` as query (`?<hash>`) for dynamic image and icon
routes as well.
* Merge the metadata image info extration into 1 single loader, dynamic
and static image route will all pass through
`next-metadata-image-loader` to extract the image info such as size,
content type, etc.
* Applying same cache header from `@vercel/og`, for development we use
"no cache" header, for production, we use "long cache" header
Closes NEXT-882
