Input: UDP Client to provide motion and touch controls

An implementation of the cemuhook motion/touch protocol, this adds the
ability for users to connect several different devices to citra to send
direct motion and touch data to citra.

src/core/settings.h

@@ -95,6 +95,8 @@ struct Values {
     std::array<std::string, NativeAnalog::NumAnalogs> analogs;
     std::string motion_device;
     std::string touch_device;
+    std::string udp_input_address;
+    u16 udp_input_port;
 
     // Core
     bool use_cpu_jit;