Move qthing includes to their own dir and clean up

qthing/util.cpp

-#include <qthing.hpp>
+#include "qthing_legacy.hpp"
+
 #include "util.hpp"
 
 #include <sstream>
@@ -7,24 +8,24 @@
 #include "freertos/task.h"
 #include "lwip/sockets.h"
 
-unsigned long IRAM_ATTR millis() {
+unsigned long IRAM_ATTR qthing::millis() {
     return xTaskGetTickCount() * portTICK_PERIOD_MS;
 }
 
-std::string to_string(float value, int precision) {
+std::string qthing::to_string(float value, int precision) {
     std::stringstream stream;
     stream.precision(precision);
     stream << value;
     return stream.str();
 }
 
-std::string to_string(uint32_t value) {
+std::string qthing::to_string(uint32_t value) {
     std::stringstream stream;
     stream << value;
     return stream.str();
 }
 
-std::string to_string(struct sockaddr_in6 sourceAddr) {
+std::string qthing::to_string(struct sockaddr_in6 sourceAddr) {
     char addr_str[128];
 
     if (sourceAddr.sin6_family == PF_INET) {