Refactor UART handling and enhance user data structures

src/main.c

@@ -10,20 +10,7 @@
 
 #include "users.h"
 #include "tui.h"
-
-void *uartListener(void *arg)
-{
-    char *uart_address = (char *)arg;
-    int uart = open(uart_address, O_RDWR | O_NOCTTY | O_NDELAY);
-    if (uart == -1)
-    {
-        perror("Failed to open UART");
-        return NULL;
-    }
-
-    close(uart);
-    return NULL;
-}
+#include "rfid_handler.h"
 
 int main(int argc, char const **argv)
 {