input_common, common: Add a few functions

These functions include reloading udp client, testing communication and configuring calibration. I also added a function to common/thread.h to use WaitFor.

src/input_common/udp/udp.h

@@ -16,6 +16,7 @@ class State {
 public:
     State();
     ~State();
+    void ReloadUDPClient();
 
 private:
     std::unique_ptr<Client> client;