Implement new logger API

[Neverlord]

Based on the design outlined in #408. I've designed it in a way that allow us to easily switch to std::format once we have access to it. Compared to the preliminary design in the ticket, I've merged the two store components back into one. There's also an app category, that I plan on using in some of our Broker tools. Broker itself won't use this component.

If we can agree on this approach, I'd prepare a branch in Zeek that picks up the logs from Broker and puts them into broker.log.