add/delete constructors and assign operators for the parser, refactor some code, update unit tests

test/test_parser.cpp

@@ -56,6 +56,9 @@ TEST_CASE("testing parser") {
     make_and_write(f.name, data);
     {
         ss::parser p{f.name, ","};
+        ss::parser p0{std::move(p)};
+        p = std::move(p0);
+
         p.set_error_mode(ss::error_mode::error_string);
         std::vector<X> i;