Pull request: websvc-config-manager

Merge in DNS/adguard-home from websvc-config-manager to master

Squashed commit of the following:

commit 2143b47c6528030dfe059172888fddf9061e42da
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Oct 4 14:50:47 2022 +0300

    next: add config manager

main_next.go

@@ -0,0 +1,21 @@
+//go:build next
+// +build next
+
+package main
+
+import (
+	"embed"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/next/cmd"
+)
+
+// Embed the prebuilt client here since we strive to keep .go files inside the
+// internal directory and the embed package is unable to embed files located
+// outside of the same or underlying directory.
+
+//go:embed build2
+var clientBuildFS embed.FS
+
+func main() {
+	cmd.Main(clientBuildFS)
+}