Updates #2915. Squashed commit of the following: commit b907324426c87ee7334edbd61e43c44444ad27a9 Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Wed Apr 7 16:26:41 2021 +0300 all: imp docs, upd commit c022f75cac006e077095cad283fea0a91d3a0eea Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Wed Apr 7 15:51:30 2021 +0300 all: add idna handling, imp domain validation