Refactor higher level code into TorrentRead class

This also addresses the issue with paths of more than 1 item
so all torrents should now work and adds some error reporting
through exceptions

src/parser.hpp

@@ -23,11 +23,18 @@
 #include <vector>
 #include <array>
 #include <cstdint>
+#include <stdexcept>
 
 namespace duck {
 typedef std::string_view TorrentStringType;
 typedef signed long long int TorrentIntType;
 
+class ParseError : public std::runtime_error {
+public:
+	ParseError (const std::string& desc);
+	~ParseError() noexcept = default;
+};
+
 struct TorrentValue : public boost::spirit::x3::variant<
 	TorrentIntType,
 	TorrentStringType,