refactor: 💡 fastaddr - moved to fastip package
Refactored the code, changed the way we prepare reply, fixed a couple of bugs on the way, added more unit tests

Squashed commit of the following:

commit 7701c2816aee1bfcd61e92e96787e0177129ce55
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 19:08:52 2020 +0300

    refactor: 💡 added a bit more logging

commit 5f184fc60f2f6e01f265b10005382821ef0cb02f
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 18:35:44 2020 +0300

    docs: ✏️ added fastip to docs

commit 2f206a6170e527c83481e57717f166958969b1ed
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 18:29:11 2020 +0300

    fix: 🐛 windows unit-tests

commit 8f38a348715c8108293ec3a41787f3a2a4f62f2a
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 18:25:16 2020 +0300

    fix: 🐛 more fixes for Windows

commit f7ad52b3b62a1ead0fcd714483f0648b86df9d1e
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 17:57:15 2020 +0300

    fix: 🐛 more logging for win

commit 7218ecafede02d655ac084aa601798d5c883ba44
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 17:46:06 2020 +0300

    fix: 🐛 more logging for Windows

commit 700ceb254949e389328a07b3b07e6e2e1cfbff83
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 17:34:57 2020 +0300

    fix: 🐛 added logging to the test to check it on Win

commit 721a4017d49708a3e7470ace777dafcbf5218404
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 16:49:26 2020 +0300

    fix: 🐛 TestPingFail on Windows

commit a990b2e7e82791b41dae1a73df731a25a61d60db
Author: Andrey Meshkov <am@adguard.com>
Date:   Sun Apr 26 16:39:20 2020 +0300

    refactor: 💡 fastaddr - moved to fastip package

    Refactored the code, changed the way we prepare reply, fixed a couple of
    bugs on the way, added more unit tests