Hover on names bound by do-notation shows type spuriously wrapped in monad

[jacg]

For example, in do xxx <- Just True the type of xxx is Bool, but hover reports it as Maybe Bool.

The spurious wrapping only appears at the bidning site; hover shows the correct type where the name is used.

Tests demonstrating this issue are available in haskell/ghcide#238.

[jacg]

A similar problem occurs in list comprehensions.

Tests showing this have been added to haskell/ghcide#238.