feat(xan): Use Witherable in the prelude

Install the witherable library, expose it in the prelude, and update all
call sites that are broken by that change.

This is a really nice library, and basically the ideal abstraction layer
for what it does.

Change-Id: I640e099318c1ecce0ad483bc336c379698bdab88
Reviewed-on: https://cl.tvl.fyi/c/depot/+/725
Reviewed-by: glittershark <grfn@gws.fyi>

users/glittershark/xanthous/src/Xanthous/Data/VectorBag.hs

@@ -35,6 +35,7 @@ newtype VectorBag a = VectorBag (Vector a)
     , Semigroup
     , Arbitrary
     , CoArbitrary
+    , Filterable
     )
 makeWrapped ''VectorBag
 
@@ -59,6 +60,11 @@ instance AsEmpty (VectorBag a) where
     (VectorBag Empty) -> Just ()
     _ -> Nothing
 
+instance Witherable VectorBag where
+  wither f (VectorBag v) = VectorBag <$> wither f v
+  witherM f (VectorBag v) = VectorBag <$> witherM f v
+  filterA p (VectorBag v) = VectorBag <$> filterA p v
+
 {-
     TODO:
     , Ixed