Add PactPollResponses module

This is a small step in reducing downstream projects' reliance
on pact types. Some projects can't keep apace with both pact's (and
chainweb's) need to use very recently published GHC versions.

chainweb-api.cabal

@@ -64,6 +64,7 @@ library
     Chainweb.Api.NodeInfo
     Chainweb.Api.PactCommand
     Chainweb.Api.PactNumber
+    Chainweb.Api.PactPollResponses
     Chainweb.Api.ParsedNumbers
     Chainweb.Api.Payload
     Chainweb.Api.RespItems

lib/Chainweb/Api/PactPollResponses.hs

@@ -0,0 +1,60 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+module Chainweb.Api.PactPollResponses where
+
+------------------------------------------------------------------------------
+import           Data.Aeson
+import           Data.Hashable (Hashable)
+import qualified Data.HashMap.Strict as HM
+import           Data.Int
+import           Data.Text (Text)
+import           Data.Word
+------------------------------------------------------------------------------
+
+newtype RequestKey = RequestKey { unRequestKey :: Text }
+  deriving (Eq, Ord, Show, Hashable, FromJSON, FromJSONKey, ToJSON, ToJSONKey)
+
+newtype TxId = TxId Word64
+  deriving (Eq, Ord, Show, FromJSON, ToJSON)
+
+newtype PactResult = PactResult { unPactResult :: Either Value Value }
+  deriving (Eq, Show, FromJSON, ToJSON)
+
+newtype Gas = Gas Int64
+  deriving (Eq, Ord, Show, FromJSON, ToJSON)
+
+data CommandResult l = CommandResult
+  { _crReqKey :: !RequestKey
+  , _crTxId :: !(Maybe TxId)
+  , _crResult :: !PactResult
+  , _crGas :: !Gas
+  , _crLogs :: !(Maybe l)
+  , _crContinuation :: !(Maybe Value) -- just accept the json?
+  , _crMetaData :: !(Maybe Value)
+  , _crEvents :: [Value] -- just accept the json?
+  } deriving (Eq, Show)
+
+instance FromJSON l => FromJSON (CommandResult l) where
+  parseJSON = withObject "CommandResult" $ \o -> CommandResult
+      <$> o .: "requestKey"
+      <*> o .:? "txId"
+      <*> o .: "result"
+      <*> o .: "gas"
+      <*> o .:? "logs"
+      <*> o .:? "continuation"
+      <*> o .:? "metadata"
+      <*> (events <$> o .: "events")
+    where
+      events Nothing = []
+      events (Just es) = es
+
+newtype PactHash = PactHash { unHash :: Text }
+  deriving (Eq, Ord, Show, FromJSON, ToJSON)
+
+newtype PollResponses = PollResponses
+  { _prResults :: HM.HashMap RequestKey (CommandResult PactHash)
+  } deriving (Eq, Show)
+
+instance FromJSON PollResponses where
+  parseJSON v = PollResponses <$> withObject "PollResponses" (\_ -> parseJSON v) v