Enhancement: Option to activate Open Graph previews when Auto Social Sharing is turned off

### Impacted plugin

Jetpack

### What

OG previews do not activate when Auto Social Sharing is turned off

### How

Open Graph (OG) previews automatically pull the site icon. But Jetpack can pull the Featured Image instead.
See thread here where we discovered this: https://wordpress.org/support/topic/outstanding-644/#post-18998838
I run Jetpack on my site but it was not pulling the Featured Image. The workaround was this plugin: https://wordpress.org/plugins/always-use-jetpack-open-graph/

Two ways to address this:
1) You could add a note to the Social Sharing setting that it needs to be turned on to activate OG previews picking up the featured image instead of the site icon
2) You could add a second toggle to the Social Sharing setting area to turn on OG previews while leaving the Auto Social Sharing setting off.

These days, most people will want OG previews (for manual sharing to iMessage, social, etc)... but lots of people won't want auto-sharing to occur.

These two things should not be attached and are mutually exclusive concerns

Thanks!