fix(golang): complete ledger support for MsgWallet{Spend}Action

refs #3628

register amino codec for WalletAction, SpendAction
... and MsgWalletSpendAction by filling in LegacyMsg methods.

This avoids:

panic: expected *legacytx.LegacyMsg when using amino JSON

golang/cosmos/x/swingset/types/codec.go

@@ -31,6 +31,8 @@ func init() {
 func RegisterCodec(cdc *codec.LegacyAmino) {
 	cdc.RegisterConcrete(&MsgDeliverInbound{}, ModuleName+"/DeliverInbound", nil)
 	cdc.RegisterConcrete(&MsgProvision{}, ModuleName+"/Provision", nil)
+	cdc.RegisterConcrete(&MsgWalletAction{}, ModuleName+"/WalletAction", nil)
+	cdc.RegisterConcrete(&MsgWalletSpendAction{}, ModuleName+"/WalletSpendAction", nil)
 }
 
 // RegisterInterfaces registers the x/swingset interfaces types with the interface registry

golang/cosmos/x/swingset/types/msgs.go

@@ -104,6 +104,28 @@ func (msg MsgWalletAction) GetSigners() []sdk.AccAddress {
 	return []sdk.AccAddress{msg.Owner}
 }
 
+// GetSignBytes encodes the message for signing
+func (msg MsgWalletAction) GetSignBytes() []byte {
+	return sdk.MustSortJSON(ModuleCdc.MustMarshalJSON(&msg))
+}
+
+// GetSignBytes encodes the message for signing
+func (msg MsgWalletSpendAction) GetSignBytes() []byte {
+	return sdk.MustSortJSON(ModuleCdc.MustMarshalJSON(&msg))
+}
+
+// Route should return the name of the module
+func (msg MsgWalletAction) Route() string { return RouterKey }
+
+// Type should return the action
+func (msg MsgWalletAction) Type() string { return "wallet_action" }
+
+// Route should return the name of the module
+func (msg MsgWalletSpendAction) Route() string { return RouterKey }
+
+// Type should return the action
+func (msg MsgWalletSpendAction) Type() string { return "wallet_spend_action" }
+
 // ValidateBasic runs stateless checks on the message
 func (msg MsgWalletAction) ValidateBasic() error {
 	if msg.Owner.Empty() {