service: plumb contexts to all (most) threads (#7363)

This continues the push of plumbing contexts through tendermint. I
attempted to find all goroutines in the production code (non-test) and
made sure that these threads would exit when their contexts were
canceled, and I believe this PR does that.

node/public.go

@@ -68,7 +68,7 @@ func New(
 			config.DefaultDBProvider,
 			logger)
 	case config.ModeSeed:
-		return makeSeedNode(conf, config.DefaultDBProvider, nodeKey, genProvider, logger)
+		return makeSeedNode(ctx, conf, config.DefaultDBProvider, nodeKey, genProvider, logger)
 	default:
 		return nil, fmt.Errorf("%q is not a valid mode", conf.Mode)
 	}