Native types were parsed directly to data_type, where varchar and text were
parsed to utf8_type. To get the name of the type there was a call to
the data_type method thus getting the name of the varchar type returns "text".
To fix this, added new nonterminal type_unreserved_keyword, which parse native
types to their names. It replaced native_or_internal_type in unreserved_function_keyword.
unreserved_function_keyword is also used to parse usernames, keyspace names, index names,
column identifieres, service levels and role names, so this bug was repaired also in them.
Fixes: #10642Closes#10960