Add support for common table expressions and window functions

[ndm2]

Now to the main show, this adds support for common table expressions and window functions.

I would have liked to add additional nesting on new lines for the FILTER() and OVER() clauses, eg:

GROUP_CONCAT(b, '.')
  FILTER (
    WHERE
      c != 'two'
  )
  OVER (
    ORDER BY
      a
  )
  AS filtered,

however without a larger rewrite of the formatter, all I could come up with was pretty hack-ish, and way too much tied to this specific syntax, so for now it would still be a bit squished.

Resolves #37

[greg0ire]

@derrabus @goetas please review

[derrabus]

I'm not sure I'm the right person to review code on this repo. 😓

[greg0ire]

No worries! Let's merge then!

[ndm2]

@greg0ire Any chance that we'll see a new release somewhat soon-ish?

[greg0ire]

Yes, sorry! https://github.com/doctrine/sql-formatter/releases/tag/1.1.3

[ndm2]

Thanks for the swift response, no need to apologize :)