Pull request: all: imp updater

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

Squashed commit of the following:

commit 6ed487359e56a35b36f13dcbf2efbf2a7a2d8734
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Jun 9 16:29:35 2022 +0300

    all: imp logs, err handling

commit e930044cb619a43e5a44c230dadbe2228e9a93f5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Jun 9 15:53:35 2022 +0300

    all: imp updater

internal/aghalg/nullbool_test.go

@@ -0,0 +1,67 @@
+package aghalg_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/aghalg"
+	"github.com/AdguardTeam/golibs/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNullBool_UnmarshalJSON(t *testing.T) {
+	testCases := []struct {
+		name       string
+		wantErrMsg string
+		data       []byte
+		want       aghalg.NullBool
+	}{{
+		name:       "empty",
+		wantErrMsg: "",
+		data:       []byte{},
+		want:       aghalg.NBNull,
+	}, {
+		name:       "null",
+		wantErrMsg: "",
+		data:       []byte("null"),
+		want:       aghalg.NBNull,
+	}, {
+		name:       "true",
+		wantErrMsg: "",
+		data:       []byte("true"),
+		want:       aghalg.NBTrue,
+	}, {
+		name:       "false",
+		wantErrMsg: "",
+		data:       []byte("false"),
+		want:       aghalg.NBFalse,
+	}, {
+		name:       "invalid",
+		wantErrMsg: `unmarshalling json data into aghalg.NullBool: bad value "invalid"`,
+		data:       []byte("invalid"),
+		want:       aghalg.NBNull,
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			var got aghalg.NullBool
+			err := got.UnmarshalJSON(tc.data)
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
+
+			assert.Equal(t, tc.want, got)
+		})
+	}
+
+	t.Run("json", func(t *testing.T) {
+		want := aghalg.NBTrue
+		var got struct {
+			A aghalg.NullBool
+		}
+
+		err := json.Unmarshal([]byte(`{"A":true}`), &got)
+		require.NoError(t, err)
+
+		assert.Equal(t, want, got.A)
+	})
+}