Allow new counting in CRON

On some very large sites, we've had issues with heavy queries due to counting even if those queries are offloaded to cron. One example is a site with lots of future-published posts which transition to publish at the same moment, a large number of term relationships and lots of terms per transitioning post. Even in cron this caused problems, and it'd be great if we could allow this behavior in that context too.

I'm thinking probably adding a filter is the right way to handle this, though it would need to be pretty early to affect the plugin's setup.

Trace the plugin setup and its cron execution path to find where term counting is enabled and where an early filter could affect it. Review the counting behavior for large batches of future-published posts and term relationships; done means cron can opt out of counting through the proposed filter without changing normal behavior.

Written by the indexing model from the issue text.