Pull request: imp-tests

Merge in DNS/adguard-home from imp-tests to master

Squashed commit of the following:

commit ea5b4e7a93359ae4800f75e77d02944a4f5d2df8
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Oct 27 15:12:45 2022 +0300

    all: imp tests, use testutil

internal/aghnet/systemresolvers_others_test.go

@@ -6,6 +6,7 @@ import (
 	"context"
 	"testing"
 
+	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -17,9 +18,8 @@ func createTestSystemResolversImpl(
 	t.Helper()
 
 	sr := createTestSystemResolvers(t, hostGenFunc)
-	require.IsType(t, (*systemResolvers)(nil), sr)
 
-	return sr.(*systemResolvers)
+	return testutil.RequireTypeAssert[*systemResolvers](t, sr)
 }
 
 func TestSystemResolvers_Refresh(t *testing.T) {