mkPersist generates unbound type names since 2.14.3.2

There was a bug in #1446 that can result in mkPersist generating unbound type names. Tweaking the following test case very slightly reproduces the issue:

diff --git a/persistent/test/Database/Persist/TH/PersistWithSpec.hs b/persistent/test/Database/Persist/TH/PersistWithSpec.hs
index 25c9fff0..e006f65e 100644
--- a/persistent/test/Database/Persist/TH/PersistWithSpec.hs
+++ b/persistent/test/Database/Persist/TH/PersistWithSpec.hs
@@ -17,7 +17,7 @@ module Database.Persist.TH.PersistWithSpec where
 
 import Control.Monad
 import TemplateTestImports
-import Database.Persist.TH.PersistWith.Model as Model (IceCream, IceCreamId)
+import qualified Database.Persist.TH.PersistWith.Model as Model (IceCream, IceCreamId)
 import Language.Haskell.TH as TH
 
 mkPersistWith sqlSettings $(discoverEntities) [persistLowerCase|

The root issue is here:

https://github.com/yesodweb/persistent/blob/02b1f9fb951282b162bae5818446d020297eed5f/persistent/Database/Persist/TH.hs#L518

The first field of FTTypeCon can be a module prefix, but this code discards it, which results in unqualified references being generated in the output.

Start in persistent/Database/Persist/TH.hs around the referenced line, then reproduce the issue by applying the qualified import change in persistent/test/Database/Persist/TH/PersistWithSpec.hs. Confirm that mkPersist no longer emits unbound type names and that the affected test passes.