Prevent insert queries from failing to parse when using "vector" as a column name

[absurdfarce]

Problem appeared to be that "vector" was added as a keyword but wasn't specified as an unreserved keyword. Added it to the parsers collection of native type names which (a) also makes it an unreserved keyword and (b) seems more correct on it's face anyway.

[absurdfarce]

Possibly useful for testing purposes:

CREATE KEYSPACE test
  WITH REPLICATION = { 
   'class' : 'SimpleStrategy', 
   'replication_factor' : 1 
  };

CREATE TABLE test.foo (
    i int PRIMARY KEY,
    vector vector<float, 3>
);

i,vector
1,"[8, 2.3, 58]"
2,"[1.2, 3.4, 5.6]"
5,"[23, 18, 3.9]"

select vector from test.foo order by vector ann of [3.4, 7.8, 9.1] limit 1;

[absurdfarce]

Thanks for the review @adutra; your points are well-taken.

I think I have a good working impl incorporating your suggestions... please take another look when you have a sec!