Method TryReadUtf8

src/core/string_consumer.hpp:412–418

* Try to read a UTF-8 character, and then advance reader. */

	 * Try to read a UTF-8 character, and then advance reader.
	 */
	[[nodiscard]] std::optional<char32_t> TryReadUtf8()
	{
		auto [len, value] = this->PeekUtf8();
		if (len == 0) return std::nullopt;
		this->Skip(len);
		return value;
	}
	/**
	 * Read UTF-8 character, and advance reader.
	 * @param def Default value to return, if no valid data.