Make `cleanupTmpDir` asyncronous (returning `Aff`)

[Renegatto]

Why

This will allow a caller to work with it more accurately, catching errors if needed.

Affected issues

It should partially fix #1580, to be precise it could allow fixing incomplete Plutip cluster cleanup after tests.

Calling cleanupTmpDir from startKupo' like this

  _ <- Aff.forkAff $ logErrorWhenLeft =<< try (cleanupTmpDir process workdir)

Would prevent any event handler error from killing the app before the full plutip cluster cleanup is done.

Implementation

cleanupTmpDir :: ManagedProcess -> FilePath -> Aff Unit
cleanupTmpDir (ManagedProcess _ child _) workingDir =
  Aff.makeAff \callback -> do
    isCancelled <- Ref.new false
    let
      cancel = void $ Ref.modify (const true) isCancelled 
    ChildProcess.onExit child \_ ->
      Ref.read isCancelled >>= flip unless do
        try (_rmdirSync workingDir) >>= callback
    pure $ Aff.effectCanceler cancel