Upgrades: Add info re forced update to notification email

[kraftbj]

When a plugin or theme update is forced via the autoupdate flag (e.g. the site would not have normally automatically updated it), the notification email should provide a line informing the site owner that it was part of an auto update.

This could probably be something like an asterisk following the plugin/theme's name, with a common explainer text that it was part of a security update.

Perhaps bonus would be a link to a WordPress.org page explaining it in more detail or confirming that a particular plugin is part of an active auto update.

[kraftbj]

Similar, but not quite a duplicate of #51695. A fix there may also fix this.

[TimothyBlynJacobs]

I think this is a dupe of #51192.

[kraftbj]

@TimothyBlynJacobs Ah, I missed that when browsing the component. I think #51192 covers this. Closing as a duplicate.