improvement: use `SetIPFilter` for local addrs

Closes #40271 (closed). Supersedes !417 (closed).

This might not be just a refactor and has a potential to affect #40322 (i.e. "reduce Snowflake's private network activity"), because with this Pion is actually aware that we don't want to use private IPs, instead of us simply not sending them to the remote peer. However, I did not test it.

And in general this simplifies the code and (probably) removes the need for StripLocalAddresses, although makes us more dependent on Pion.

I'm not removing StripLocalAddresses for now just in case SetIPFilter is somehow more sloppy than what we do. However, now it should be easy to remove it if needed.