How can you set the DEFAULT to "Allow Data Storage ONLY for the Session" and CHOOSE sites to allow data storage?

It seems the default for allowing sites to store data locally is backwards (for privacy). You should be able to set the DEFAULT to "Allow all sites to store data locally FOR THE SESSION ONLY," and then type in the sites that you would like to allow to store data locally for more than one session (or block entirely). Is there a way to do this? There are not many sites I would like to allow permanent local data storage, so it wouldn't be such a terrible chore to type in their URLs. The opposite is true for sites I would want to allow ONLY FOR the one SESSION - that is a HUGE chore. This appears to be a privacy & security oversight - can you fix this?