Error messages about fundep conflicts are missing spans

Consider

{-# LANGUAGE FunctionalDependencies #-}

class Convert a b | a -> b where
  convert :: a -> b

instance Convert Int Float where
  convert = fromIntegral

instance Convert Int () where
  convert = const ()

The Curry frontend currently outputs an error message without a span:

Error:
    Functional dependency conflict between instances
      Convert Int () (defined in FunDepConflict)
      Convert Int Float (defined in FunDepConflict)

GHC, however, does:

FunDepConflict.hs:6:10: error: [GHC-46208]
    Functional dependencies conflict between instance declarations:
      instance Convert Int Float -- Defined at FunDepConflict.hs:6:10
      instance Convert Int () -- Defined at FunDepConflict.hs:9:10
  |
6 | instance Convert Int Float where
  |          ^^^^^^^^^^^^^^^^^

It would be nice if we could add spans to our error message too, that way the message can also be positioned correctly in LSP clients.