Adding support of the timestamp, fix for querying a subquery with a capital alias.

[eXigentCoder]

Support for timestamp queries

Example query, now works:

SELECT  *,
        unset(_id)
FROM orders
WHERE orderDate > timestamp '2021-01-01 00:00:00'
LIMIT 1

Ability to query SubQueries that start with a capital letter

Previously the following query would not have worked unless Order2 started with order2:

SELECT  Order1.id,
        Order1.item,
        unset(_id)
FROM orders Order1
INNER JOIN(
    SELECT * FROM orders) 'Order2|unwind' on Order2.id = Order1.id
LIMIT 1