Change infix patterns to include spaces

This commit changes infix patterns to utilize `lrdrNameToTextAnn`. This
function allows the logic to avoid introspecting on the constructor
name.

Additionally this adds spaces to all infix operator pattern matches.
Previously infix symbols did not include spaces:

```
foo (x:xs) = _
```

Now they include a space

```
foo (x : xs) = _
```

src/Language/Haskell/Brittany/Internal/Layouters/Pattern.hs

@@ -78,12 +78,10 @@ layoutPat lpat@(L _ pat) = docWrapNode lpat $ case pat of
         return $ x1 Seq.<| xR
   ConPatIn lname (InfixCon left right) -> do
     -- a :< b -> expr
-    let nameDoc = lrdrNameToText lname
-    leftDoc  <- colsWrapPat =<< layoutPat left
+    let nameDoc = lrdrNameToTextAnn lname
+    leftDoc  <- appSep . colsWrapPat =<< layoutPat left
     rightDoc <- colsWrapPat =<< layoutPat right
-    middle <- docLit $ if Text.any isAlpha nameDoc
-      then Text.pack " `" <> nameDoc <> Text.pack "` "
-      else nameDoc
+    middle <- appSep . docLit =<< nameDoc
     return $ Seq.empty Seq.|> leftDoc Seq.|> middle Seq.|> rightDoc
   ConPatIn lname (RecCon (HsRecFields [] Nothing)) -> do
     -- Abc{} -> expr