Merge in DNS/dnsproxy from upd to master

Squashed commit of the following:

commit 54950780c2bb397111a7aa953e8d8b8b15902359
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Dec 23 14:38:06 2021 +0300

    upstream: imp code

commit 0ddc6311f6b387b3de93faf739fbbde7cff1f039
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 22 21:08:13 2021 +0300

    all: upd more

commit cf987ed1228dbf97e0cfb832e79242af81b906d9
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 22 20:50:01 2021 +0300

    proxy: fmt

commit 31821af78ad83419495841fe6f0abc114151950e
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 22 20:47:44 2021 +0300

    all: upd go, simplify code