[client,signal,management] Add browser client support (#4415)

client/internal/dns/server_js.go

@@ -0,0 +1,5 @@
+package dns
+
+func (s *DefaultServer) initialize() (hostManager, error) {
+	return &noopHostConfigurator{}, nil
+}

client/internal/dns/unclean_shutdown_js.go

@@ -0,0 +1,19 @@
+package dns
+
+import (
+	"context"
+)
+
+type ShutdownState struct{}
+
+func (s *ShutdownState) Name() string {
+	return "dns_state"
+}
+
+func (s *ShutdownState) Cleanup() error {
+	return nil
+}
+
+func (s *ShutdownState) RestoreUncleanShutdownConfigs(context.Context) error {
+	return nil
+}