Add site exceptions for "clear data on close"

The option exists for third party cookie storage but not for the “clear data on exit” option. There’s a couple sites I don’t want to have to relog into every time the browser closes out.

Last two topics on this were from 4 and 5 years ago. Seems like a pretty straight forward thing to implement given that third party cookie exemption is already there.

Linking to a similar request: