Codefix: implement StrTrimInPlace without assigning a borrowed view of itself

src/console_cmds.cpp

@@ -934,8 +934,7 @@ static bool ConClientNickChange(std::span<std::string_view> argv)
 		return true;
 	}
 
-	std::string client_name(argv[2]);
-	StrTrimInPlace(client_name);
+	std::string client_name{StrTrimView(argv[2])};
 	if (!NetworkIsValidClientName(client_name)) {
 		IConsolePrint(CC_ERROR, "Cannot give a client an empty name.");
 		return true;

src/string.cpp

@@ -225,7 +225,15 @@ bool StrValid(std::span<const char> str)
  */
 void StrTrimInPlace(std::string &str)
 {
-	str = StrTrimView(str);
+	size_t first_pos = str.find_first_not_of(' ');
+	if (first_pos == std::string::npos) {
+		str.clear();
+		return;
+	}
+	str.erase(0, first_pos);
+
+	size_t last_pos = str.find_last_not_of(' ');
+	str.erase(last_pos + 1);
 }
 
 std::string_view StrTrimView(std::string_view str)