Pull request #886: all: allow multiple rules in dns filter results

Merge in DNS/adguard-home from 2102-rules-result to master

Updates #2102.

Squashed commit of the following:

commit 47b2aa94c56b37be492c3c01e8111054612d9722
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Dec 17 13:12:27 2020 +0300

    querylog: remove pre-v0.99.3 compatibility code

commit 2af0ee43c2444a7d842fcff057f2ba02f300244b
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Dec 17 13:00:27 2020 +0300

    all: improve documentation

commit 3add300a42f0aa67bb315a448e294636c85d0b3b
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 16 18:30:01 2020 +0300

    all: improve changelog

commit e04ef701fc2de7f4453729e617641c47e0883679
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 16 17:56:53 2020 +0300

    all: improve code and documentation

commit 4f04845ae275ae4291869e00c62e4ff81b01eaa3
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 16 17:01:08 2020 +0300

    all: document changes, improve api

commit bc59b7656a402d0c65f13bd74a71d8dda6a8a65d
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Dec 15 18:22:01 2020 +0300

    all: allow multiple rules in dns filter results

internal/querylog/qlog_test.go

@@ -236,10 +236,12 @@ func addEntry(l *queryLog, host, answerStr, client string) {
 	a.Answer = append(a.Answer, answer)
 	res := dnsfilter.Result{
 		IsFiltered:  true,
-		Rule:        "SomeRule",
 		Reason:      dnsfilter.ReasonRewrite,
 		ServiceName: "SomeService",
-		FilterID:    1,
+		Rules: []*dnsfilter.ResultRule{{
+			FilterListID: 1,
+			Text:         "SomeRule",
+		}},
 	}
 	params := AddParams{
 		Question:   &q,