Feature request: Add dedicated cron call for crawler

On multisite environments when the crawler is active, all crawlers for the subsites of the multisite network are triggered at the same time which could lead to heavy loads for a certain amount of time.

Especially, it would be beneficial to many users to be able to run the crawlers via cron command to specific low-traffic times.

No files, tests, or entry points are identified in the issue. Start by locating the multisite crawler trigger and the plugin’s cron or command integration, then define how a dedicated cron call targets specific low-traffic times without triggering all subsites together; done means the crawler can be scheduled separately for multisite subsites.

Written by the indexing model from the issue text.