Add a flag in `plugin list` and `theme list` commands to skip force update-check

[Nikhil]

Feature Request

• Yes, I reviewed the contribution guidelines.

Describe your use case and the problem you are facing

We have a case where a managed WordPress hosting provider daily runs some routine site status checks in which they run wp plugin list and wp theme list commands. This runs at a time on tens of thousands of sites at a time.

Being a premium plugin developer, who has a common user base with a hosting provider we get hammered with a bulk requests when this activity happens at the hosting provider, since as a standard practice in WordPress, We hook onto update_plugins and update_themes transient updates and make requests to our servers as well at the time to add update information related to premium products.

Describe the solution you'd like

A force update-check can be skipped in this use case as wp plugin list and wp theme list should be able to get the already available information in the update transients.

Currently it is possible to bypass force update-check by setting WP_INSTALLING constant, although WP-CLI changes the update transients to null if WP_INSTALLING constant is set, hence this solution does not satisfy complete requirements.

A dedicated flag (eg. --skip-update-check) to bypass the upgrade_refresh would work as expected in this situation.