Handle query autocomplete starting with SELECT

[Westwooo]

For the new query autocomplete feature we start with FROM instead of SELECT, e.g: FROM collection SELECT ....

This is because we need to know the collection being queried before we can give a list of the fields the user may like to retrieve. The issue with this is that it is likely not going to be expected by users with prior n1ql experience, since they will expect to start with a SELECT. We should add a SELECT command that autofills the field to * then have it proceed as FROM does after that.