Summary:
This is the first of many diffs that extracts the connection, device, client detection out of the flipper core, to create a reusable flipper-server library that can be used in e.g. flipper-dump.
To keep diffs a little smaller, the current connection logic is first moved to the `server/` directory, and decoupled manually from the rest of the core, before moving it over to a separate package.
This first diffs moves the `comms/`, `devices/` and certificate utilities to the `server` directory.
Further untangling will follow in next diffs
Reviewed By: timur-valiev
Differential Revision: D30246551
fbshipit-source-id: c84259bfb1239119b3267a51b015e30c3c080866
5e8c968222