Fix unwanted import refinement

[rayshih]

The problem

If module F imports and exports G, but it also has it's own bindings defined like this:

module F (module F, module G) where

import G

f1 :: String
f1 = "f1"

And the usage of F is

import F (f1, g1)

before this pr it will suggest refinement like

import G (g1)

This is definitely wrong.

The correct one should be not suggesting refinement in this case, since f1 is definitely needed, so does module F

See the attached test change for full example

[jneira]

thanks for the fix