Add user ID to wp_logout action

[TimothyBlynJacobs]

As pointed out by @figureone, after #35488, the logged out user's id is no longer accessible when the wp_logout action is fired.

I think it would be a good idea to get the current user's id before starting the logout and then passing that id to the logout filter. As @figureone pointed out, the clear_auth_cookie hook can be used as a stop-gap, but I think the change is still valuable since the two aren't equivalent actions. Auth cookies are cleared in other places, not just when the user is logging out.

[figureone]

This is actually what we did manually, after a report of an incompatibility with another plugin (User Switching) after we switched from the wp_logout to clear_auth_cookie hook. Now we grab the user ID in clear_auth_cookie, and then reference it in wp_logout.
​https://github.com/uhm-coe/authorizer/commit/30d902be01f17d414fc18179cfb3e84a916499f4
​https://github.com/uhm-coe/authorizer/issues/91

Adding user ID as a param to wp_logout would simplify this for us.

[rebasaurus]

Added pre_wp_logout action before used is logged out.

[donmhico]

49533.2.diff is different compared to 49533.patch as it tries to follow the suggested approach by @TimothyBlynJacobs.

[SergeyBiryukov]

In 47553:

Users: Pass the ID of the user that was logged out to the wp_logout action.

Props donmhico, figureone, TimothyBlynJacobs, rebasaurus.
Fixes #49533.