[haskell][server]: Set "AnyType" to Aeson.Value (#9733)

* [haskell][server]: Set "AnyType" to `Aeson.Value`

`AnyType` would not be translated to the json value type.
This fixes that.

* [haskell][server] Fix haddock error in `API.hs`

Haddock (the Haskell documentation generator) would choke on the
misplaced docstring. The heading has to appear inside the list.

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellServantCodegen.java

@@ -201,6 +201,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         typeMapping.put("number", "Double");
         typeMapping.put("BigDecimal", "Double");
         typeMapping.put("any", "Value");
+        typeMapping.put("AnyType", "Value");
         typeMapping.put("UUID", "UUID");
         typeMapping.put("URI", "Text");
         typeMapping.put("ByteArray", "Text");

modules/openapi-generator/src/main/resources/haskell-servant/API.mustache

@@ -14,8 +14,8 @@
 -fno-warn-unused-binds -fno-warn-unused-imports -freduction-depth=328 #-}
 
 module {{title}}.API
-  -- * Client and Server
-  ( Config(..)
+  ( -- * Client and Server
+    Config(..)
   , {{title}}Backend(..)
   , create{{title}}Client
   , run{{title}}Server