[5.x] Added the ability for Protectors to allow static caching

[kingsven]

This PR provides the ability for protected entries to be allowed in the static cache and addresses the concerns outlined in the comments on #10929

It also may be worth considering either defaulting statamic.protect.cacheable to true on update of statamic/cms so that the original behaviour doesn't change for existing deployments. Any thoughts/feedback on this?

Closes statamic/ideas#1234.

[jasonvarga]

Thanks for this.

I can't see a good reason to let people add 'cacheable' => true in their config.

The whole reason we made "fix" where protected pages aren't cached is so that people don't unintentionally make private pages public. Adding a setting just lets people opt into that flaw, maybe unintentionally.

A custom driver though, sure. In your case you've said that your driver is smart and can know more about the cache.

So unless you have a compelling argument against it, would you mind reverting the config, and just allow drivers to override their own cacheable method? The Protector@cacheable method can just return false.

Even if you wanted to make the IP driver cacheable, for example, you could make a custom driver that extends ours and just override the cacheable method.