Pull request 1799: AG-21072-stats-conf-race

Merge in DNS/adguard-home from AG-21072-stats-conf-race to master

Squashed commit of the following:

commit 26843b70ab8bfe0fa110c4156f2fd3f53ec5ee74
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 4 20:30:22 2023 +0300

    all: imp docs, locks

commit 942a5baa9606376dd06a3ef3284c17133014f768
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 4 19:15:18 2023 +0300

    stats: fix conf races

internal/stats/http_test.go

@@ -24,11 +24,11 @@ func TestHandleStatsConfig(t *testing.T) {
 	)
 
 	conf := Config{
+		UnitID:         func() (id uint32) { return 0 },
+		ConfigModified: func() {},
 		Filename:       filepath.Join(t.TempDir(), "stats.db"),
 		Limit:          time.Hour * 24,
 		Enabled:        true,
-		UnitID:         func() (id uint32) { return 0 },
-		ConfigModified: func() {},
 	}
 
 	testCases := []struct {