Allows ENS-like names as identifiers in our SQL parser

[brunocalza]

We need to support at least the . (dot) as an allowed character for identifiers to enable the ENS experiment.

In SQLite, the . is only allowed inside an identifier when the identifier is between double quotes, square brackets, or backticks.
That means, select * from .; should not be allowed but select * from [.]; should.

So, as a result, ENS-like names can only be used inside double quotes, square brackets, or backticks.