Core/ChatCommands: make ExactSequence more readable

(cherry picked from commit feaaa595ca)

src/common/Utilities/Util.cpp

@@ -840,11 +840,6 @@ bool StringEqualI(std::string_view str1, std::string_view str2)
                       });
 }
 
-bool StringStartsWith(std::string_view haystack, std::string_view needle)
-{
-    return (haystack.substr(0, needle.length()) == needle);
-}
-
 bool StringContainsStringI(std::string_view haystack, std::string_view needle)
 {
     return haystack.end() !=