Extend imports broken when more than one option

[pepeiborra]

Description: ghcide cannot handle GHC error messages suggesting more than one import to be extended:

• Variable not in scope:
    intercalate :: [Char] -> [[Char]] -> String
• Perhaps you want to add ‘intercalate’
  to one of these import lists:
    ‘Data.List’ (/home/pepe/scratch/testbox/MyLib.hs:3:1-19)
    ‘GHC.OldList’ (/home/pepe/scratch/testbox/MyLib.hs:4:1-21)

Expected behavior - the following code actions:

• Add 'intercalate' to the import list of GHC.OldList
• Add 'intercalate' to the import list of Data.List

Actual behavior - the following code actions which result in duplicate imports:

• import GHC.OldList (intercalate)
• import Data.List (intercalate)

Full code:

module MyLib where
import Data.List ()
import GHC.OldList ()

someFunc :: IO ()
someFunc = putStrLn $ intercalate " " ["hi", "world"]

[gdevanla]

I believe this is fixed with haskell/ghcide#913