Update test output for exception CLC proposals

The following two proposals add exception type info to the output
of displayException:

haskell/core-libraries-committee#231
haskell/core-libraries-committee#261

This commit updates the test output here to match:

https://gitlab.haskell.org/ghc/ghc/-/merge_requests/12242

Author: tbidne

tests/stm055.stderr

@@ -1 +1,7 @@
-stm055: Control.Concurrent.STM.atomically was nested
+stm055: Exception:
+
+Control.Concurrent.STM.atomically was nested
+
+Package: ghc-internal
+Module: GHC.Internal.Control.Exception.Base
+Type: NestedAtomically