Provide mechanism to easily turn off optimizations applied by Optimization Detective for lab testing

[westonruter]

Feature Description

As sites start to adopt Optimization Detective and their pages are optimized, it would be very useful to be able to compare how the page loads with the optimizations applied as well as with the optimizations absent. This would allow us to do lab testing for live sites to see the impact. This would avoid us having to find sites in CrUX or HTTP Archive that used to not have the plugin and then got the plugin installed, in order to do a before/after comparison. (Granted, this should still be done with CrUX to get actual field impact.)

This could be done simply by adding a query parameter to the URL, for example ?disable-optimization-detective=1.

[westonruter]

Humm, this would also be relevant to Embed Optimizer and other plugins. Should we have a common mechanism (public interface) to disable certain performance features for a specific request?