Add p2p-denylist flag

See https://github.com/ipfs/js-ipfs/issues/3982 for context

Implementation example from Prysm https://github.com/prysmaticlabs/prysm/blob/23e39d3d6451aff2dc302f78923abdc13767237d/cmd/flags.go#L167

Potential library to use (used by libp2p in their address sorter https://github.com/libp2p/js-libp2p-utils/blob/master/src/address-sort.js) https://www.npmjs.com/package/private-ip

**TODO**
- Benchmark the performance cost of `private-ip`
- Ensure that libp2p only runs the address sorter once per peer

Read the context in ipfs/js-ipfs#3982, then compare the Prysm flags.go example with libp2p's address-sort.js and the private-ip package. Benchmark private-ip's performance cost and verify that libp2p runs the address sorter only once per peer; done means the p2p-denylist flag works with those costs and call-count concerns addressed.

Written by the indexing model from the issue text.