Add Proxy Support

[dumprop]

Currently adguard for android have 2 methods of filtering: local vpn and proxy, which need a root access
But using proxy is allowed without root access (it needs only for server)
I want to setup adguard proxy on my AdGuardHome server and then use it on my phone (other devices)
It a little bit slower because need a connection to remote server, but then I can use filter ad on any device