Pull request: all: add stub binary for new api

Merge in DNS/adguard-home from new-api to master

Squashed commit of the following:

commit 83f4418c253b9abc5131d9e2acc2a4a96e4122c4
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 26 19:09:34 2022 +0300

    all: fix build

commit 1fbb53fdf779bde79fab72f9c8eb929e08bb044c
Merge: 73a55197 1c89394a
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 26 18:37:27 2022 +0300

    Merge branch 'master' into new-api

commit 73a5519723f662979bdeb5192bc15835e7f03512
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 26 18:36:50 2022 +0300

    v1: imp names, docs

commit d3fbc2f2082612b8ba438c8216c6c74421cc2df5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Apr 22 17:55:42 2022 +0300

    cmd: imp docs

commit c2a73aa364a848e8066d1132d4b53bbc3e22db2d
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Apr 22 16:19:14 2022 +0300

    all: add stub binary for new api

internal/v1/websvc/websvc_test.go

@@ -0,0 +1,69 @@
+package websvc_test
+
+import (
+	"context"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/v1/websvc"
+	"github.com/AdguardTeam/golibs/netutil"
+	"github.com/AdguardTeam/golibs/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const testTimeout = 1 * time.Second
+
+func TestService_Start_getHealthCheck(t *testing.T) {
+	c := &websvc.Config{
+		TLS: nil,
+		Addresses: []*netutil.IPPort{{
+			IP:   net.IP{127, 0, 0, 1},
+			Port: 0,
+		}},
+		SecureAddresses: nil,
+		Timeout:         testTimeout,
+	}
+
+	svc := websvc.New(c)
+
+	err := svc.Start()
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
+		t.Cleanup(cancel)
+
+		err = svc.Shutdown(ctx)
+		require.NoError(t, err)
+	})
+
+	addrs := svc.Addrs()
+	require.Len(t, addrs, 1)
+
+	u := &url.URL{
+		Scheme: "http",
+		Host:   addrs[0],
+		Path:   "/health-check",
+	}
+	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
+	require.NoError(t, err)
+
+	httpCli := &http.Client{
+		Timeout: testTimeout,
+	}
+	resp, err := httpCli.Do(req)
+	require.NoError(t, err)
+
+	testutil.CleanupAndRequireSuccess(t, resp.Body.Close)
+
+	assert.Equal(t, http.StatusOK, resp.StatusCode)
+
+	body, err := io.ReadAll(resp.Body)
+	require.NoError(t, err)
+
+	assert.Equal(t, []byte("OK"), body)
+}