fix rendering of external in quote embeds

[haileyok]

External embeds are not currently displayed in a quote post, which results in context loss.

I also think it makes more sense here to remove the .find() since - unless this is done in anticipation of future changes - there will never be more than a single embed for a post: https://github.com/bluesky-social/atproto/blob/50f70453a9e49621956e4e820226c0e220fe138e/packages/bsky/src/services/feed/views.ts#L434 (thanks @mary-ext). Instead we just need to get the first possible embed from the array.

We do still need to check for types, since we don't want to show a quote's quote.

Of course we could add

  const externalEmbed = React.useMemo(
    () =>
      quote.embeds?.find(
        embed =>
          AppBskyEmbedExternal.isView(embed)
      ),
    [quote.embeds],
  )

but this feels like some additional logic that isn't needed. Correct me if wrong.

[pfrazee]

Strong +1 to this. It was the wrong call not to do link cards.

I actually don't recall why app.bsky.embed.record#viewRecord uses an array of embeds but I assume it was for future defensibility.