Second pass at GDB monitor help command handler refactor.

Also added help text for the new `lr` and `rr` commands.

src/Services/StringService.cpp

@@ -42,11 +42,6 @@ namespace Services
         return str;
     }
 
-    std::string StringService::padRight(std::string str, char padChar, std::size_t padSize) {
-        str.insert(str.end(), str.size() < padSize ? padSize - str.size() : 0, padChar);
-        return str;
-    }
-
     std::string StringService::toHex(std::uint64_t value) {
         auto stream = std::stringstream{};
         stream << std::hex << std::setfill('0') << std::setw(16) << static_cast<unsigned int>(value);

src/Services/StringService.hpp

@@ -16,7 +16,6 @@ namespace Services
 
         static bool isAscii(const std::string& str);
         static std::string replaceUnprintable(std::string str);
-        static std::string padRight(std::string str, char padChar, std::size_t padSize);
 
         static std::string toHex(std::uint64_t value);
         static std::string toHex(std::uint32_t value);