Enabled arcs render after adapting OpenCNCPilot code.

Started porting iosender to C++

string_utils.h

@@ -1,7 +1,9 @@
 #pragma once
 
+#include <utility>
 #include <vector>
 #include <string>
+#include <algorithm>
 
 inline std::vector<std::string> split_string(const std::string& in, const std::string& delimiter) {
     std::vector<std::string> result{};
@@ -40,4 +42,39 @@ inline std::string& trim(std::string& str, const std::string& chars = "\t\n\v\f\
 
 inline std::string trim(std::string&& str, const std::string& chars = "\t\n\v\f\r ") {
     return ltrim(rtrim(str, chars), chars);
-}
+}
+
+inline std::string& to_upper(std::string& str) {
+    std::transform(str.begin(), str.end(), str.begin(),
+                   [](unsigned char c) { return std::toupper(c); });
+    return str;
+}
+
+inline std::string& to_lower(std::string& str) {
+    std::transform(str.begin(), str.end(), str.begin(),
+                   [](unsigned char c) { return std::tolower(c); });
+    return str;
+}
+
+inline std::string to_upper(std::string&& str) {
+    auto result = str;
+    return to_upper(result);
+}
+
+inline std::string to_lower(std::string&& str) {
+    auto result = str;
+    return to_lower(result);
+}
+
+inline bool string_contains(const std::string& str, const std::string& needle) {
+    return str.find(needle) != std::string::npos;
+}
+
+inline std::string remove_spaces(std::string str) {
+    str.erase(std::remove(str.begin(), str.end(), ' '), str.end());
+    return str;
+}
+
+inline bool starts_with(const std::string& line, const std::string& prefix) {
+    return line.rfind(prefix, 0) == 0;
+}