Improve syntax for Haskell files (based on sublimehq/Packages#2225)

- Match $ in keyword.operator.haskell
- Match via in meta.deriving.haskell
- Match instance declaration under newtype declaration

    -- | Derive 'Read' / 'Show' using @DerivingVia@.
    newtype Quiet a =
      Quiet {
          unQuiet :: a
        }

    instance (Generic a, QShow (Rep a)) => Show (Quiet a) where
      showsPrec n =
        qshowsPrec n . unQuiet

    instance (Generic a, QRead (Rep a)) => Read (Quiet a) where
      readPrec =
        fmap Quiet qreadPrec
- Match @# in keyword.operator.haskell
- Match @# in entity.name.function.infix.haskell
- Add scope support.function.prelude.haskell
- Sort support.function.prelude.haskell
- Base support.function.prelude.haskell on language-haskell haskell.cson
  https://github.com/atom-haskell/language-haskell/blob/e036e449909816e616b880157e2703e70fc9b5df/grammars/haskell.cson
- Sync syntax_test_haskell.hs with upstream
  https://github.com/sublimehq/Packages/blob/549ee49a38d4b77bcb1df068ef2c122a3bec75e7/Haskell/syntax_test_haskell.hs
- Match type signatures that are split in newlines
- Set name as Haskell (λ)
- Test OPTIONS_HADDOCK
- Test via (deriving)
- Test type signatures that are split in newlines
- Test keyword.operator.haskell (*, @, and #)
- Test entity.name.function.infix.haskell (:@, and :#)