Remove 'certifying' type of redeemers in the API

  I've mistakenly messed up when introducing this one originally an the type is plain wrong (it's Byron's certificate where it should be Shelley's). For now, the focus is on getting the balancing endpoint to work, and the case of redeemers for certificates is quite an edge-case, so it can be addressed in subsequent PRs.

lib/core/src/Cardano/Wallet/Api/Types.hs

@@ -162,7 +162,6 @@ module Cardano.Wallet.Api.Types
     , ApiBalanceTransactionPostData (..)
     , ApiExternalInput (..)
     , ApiRedeemer (..)
-    , ApiRedeemerCertificate (..)
 
     -- * API Types (Byron)
     , ApiByronWallet (..)
@@ -1022,16 +1021,8 @@ data ApiRedeemer (n :: NetworkDiscriminant)
     = ApiRedeemerSpending ApiRedeemerData (ApiT TxIn)
     | ApiRedeemerMinting ApiRedeemerData (ApiT W.TokenPolicyId)
     | ApiRedeemerRewarding ApiRedeemerData (ApiT W.RewardAccount, Proxy n)
-    | ApiRedeemerCertifying ApiRedeemerData ApiRedeemerCertificate
     deriving (Eq, Generic, Show)
 
-data ApiRedeemerCertificate = ApiRedeemerCertificate
-    { delegator :: !(ApiT (VerificationKey PaymentKey))
-    , delegate :: !(ApiT (VerificationKey PaymentKey))
-    , epochNumber :: !(ApiT EpochNo)
-    , signature :: !(ApiBytesT 'Base16 ByteString)
-    } deriving (Eq, Generic, Show)
-
 instance ToJSON (ApiT (VerificationKey PaymentKey)) where
     toJSON = toJSON . serialiseToBech32 . getApiT
 instance FromJSON (ApiT (VerificationKey PaymentKey)) where
@@ -2744,8 +2735,6 @@ instance DecodeStakeAddress n => FromJSON (ApiRedeemer n) where
                 ApiRedeemerMinting bytes <$> (o .: "policy_id")
             "rewarding" ->
                 ApiRedeemerRewarding bytes <$> (o .: "stake_address")
-            "certifying" ->
-                ApiRedeemerCertifying bytes <$> (o .: "certificate")
             _ ->
                 fail "unknown purpose for redeemer."
 instance EncodeStakeAddress n => ToJSON (ApiRedeemer n) where
@@ -2765,16 +2754,6 @@ instance EncodeStakeAddress n => ToJSON (ApiRedeemer n) where
             , "data" .= bytes
             , "stake_address" .= addr
             ]
-        ApiRedeemerCertifying bytes cert -> object
-            [ "purpose" .= ("certifying" :: Text)
-            , "data" .= bytes
-            , "certificate" .= cert
-            ]
-
-instance FromJSON ApiRedeemerCertificate where
-    parseJSON = genericParseJSON defaultRecordTypeOptions
-instance ToJSON ApiRedeemerCertificate where
-    toJSON = genericToJSON defaultRecordTypeOptions
 
 instance (DecodeStakeAddress n, DecodeAddress n)
     => FromJSON (ApiBalanceTransactionPostData n)