Activity comment / Post comment sync: Spammed activity does not spam the corresponding comment

[imath]

While working #6482 on adding some unit tests to feel a bit more secure when i'll have to edit some blogs functions, i've noticed that a comment synced with an activity is not marked as spam when the corresponding activity comment is marked as spam.

See one of the unit tests i've built for #6482, i'm attaching to this ticket.

[imath]

@r-a-y should i deal with it inside of #6482 with a generic function for all post types, or should we deal with it for the post post type first ?

[imath]

This ticket will be fixed when #6482 will be committed :)

[imath]

In 10544:

Post Type Activities: generalize the Blogs component "post" comment synchronization feature to any post type.

As soon as the Blogs component is active and activity comments about Post Type activities are not disallowed, a new comment added to a post type will generate an activity comment about the corresponding Post Type Activity and vice versa.

Deprecate the Blogs component functions previously used to track the "post" post type in favor of the Activity component functions introduced in r10543.

Only load the Blogs component activity functions if the Activity component is active.

Make sure a synchronized activity comment marked as spam is also marking as spam the corresponding post type comment.

NB: some unit tests will temporarly fail after this commit. Next commit will fix the failing tests.

Props shanebp, r-a-y.

See #6482
Fixes #6793