Custom IP blacklists

[GyulyVGC]

Allow users to import a custom IP blacklist.

When a connection with a blacklisted IP is established, the user should be notified, and the connection should be highlighted in some way.

This is a first step in the direction of making it possible to identify suspicious/malicious traffic.

Originally posted by @ZeroDot1 in #685 (comment)

[GyulyVGC]

@ZeroDot1 I noticed your CoinBlockerLists! Good job!

Maybe when this feature will be implemented we can collaborate to introduced them in Sniffnet if there is proven potential.

However this won't happen shortly because I have other items to implement before.

[ZeroDot1]

Hi @GyulyVGC, thank you very much, I have put the #CoinBlockerLists project on ice (see: WaLLy3K/wally3k.github.io#215 ) due to health reasons and high costs. But I am happy to help with testing the function for IPs and domains.