Add support for protobuf TxGenerator and SIGN_MODE_DIRECT (#6385)

* Add TxWrapper, encoder, decoder and DirectModeHandler

* fix pkg name

* Update API and leave test TODO's

* Update TxWrapper API

* tests for tx wrapper (#6410)

* WIP: added test for direct mode handler

* updated code

* Add msg

* Update TxWrapper API

* Fix pubkey declaration

* Add pubkey for tests

* Fix SetFee

* Remove logs

* Avoid global var declaration for tests

* Add test for GetPubKeys

* Fix direct signing tests

* Add more test cases for GetSignBytes

* Revert SetFee API

* Remove logs

* Refactor tests

Co-authored-by: anilCSE <anil@vitwit.com>
Co-authored-by: sahith-narahari <sahithnarahari@gmail.com>

* Refactoring

* Refactoring

* Integrate SignatureV2 API

* Fix wrapper tests

* Fix tests

* Linting and API tweaks

* Update API

* WIP on updating API

* Fix tests

* Update to new SigVerifiableTx

* Rename

* Update docs to reflect ADR 020

* proto-gen

* proto docs

* cleanup

* cleanup

* cleanup

* cleanup

* cleanup

* cleanup

* cleanup

* Add tests

* Refactor and improving test coverage

* WIP on test coverage

* WIP on test coverage

* proto-gen

* Fix CompactBitArray.Size() bug

* Rename

* Remove Builder interface

* Address review comments

* Update x/auth/tx/sigs.go

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

* Update x/auth/tx/encoder.go

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

* Update x/auth/tx/encoder.go

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

* Address review feedback

* Fix build issues

* Resolve conflicts

* Fix ValidateBasic test coverage

* Add test for malicious multisig

Co-authored-by: atheeshp <59333759+atheeshp@users.noreply.github.com>
Co-authored-by: anilCSE <anil@vitwit.com>
Co-authored-by: sahith-narahari <sahithnarahari@gmail.com>
Co-authored-by: Alexander Bezobchuk <alexanderbez@users.noreply.github.com>
Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

codec/proto_codec.go

@@ -125,7 +125,12 @@ func (pc *ProtoCodec) UnmarshalJSON(bz []byte, ptr interface{}) error {
 		return fmt.Errorf("cannot protobuf JSON decode unsupported type: %T", ptr)
 	}
 
-	return jsonpb.Unmarshal(strings.NewReader(string(bz)), m)
+	err := jsonpb.Unmarshal(strings.NewReader(string(bz)), m)
+	if err != nil {
+		return err
+	}
+
+	return types.UnpackInterfaces(ptr, pc.anyUnpacker)
 }
 
 func (pc *ProtoCodec) MustUnmarshalJSON(bz []byte, ptr interface{}) {