non breaking signbytes (#5008)

* test-vectors for backwards compatibility:

 - copy & paste test-vectors from v0.33.5 to ensure
 backwards compatibility for vote's SignBytes

* WIP: everything besides time seems to match :-/

* almost

* Found the culprit: field nums weren't consecutive ints ...

* fix order of partset header too

* this last votes-related test can easily be fixed

* some minor changes and fix last failing test

* move proto types back to stdtime, fix various linting

* use libs/protoio

* remvoe commented code

* add comments

* fix tests

* uncomment testscases

* dont ignore error panic

* fix signable test

* fix happy path testing

* fix comment

Co-authored-by: Marko Baricevic <marbar3778@yahoo.com>

types/vote.go

@@ -6,10 +6,9 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/gogo/protobuf/proto"
-
 	"github.com/tendermint/tendermint/crypto"
 	tmbytes "github.com/tendermint/tendermint/libs/bytes"
+	"github.com/tendermint/tendermint/libs/protoio"
 	tmproto "github.com/tendermint/tendermint/proto/types"
 )
 
@@ -87,10 +86,11 @@ func (vote *Vote) CommitSig() CommitSig {
 // If any error arises this will panic
 func VoteSignBytes(chainID string, vote *tmproto.Vote) []byte {
 	pb := CanonicalizeVote(chainID, vote)
-	bz, err := proto.Marshal(&pb)
+	bz, err := protoio.MarshalDelimited(&pb)
 	if err != nil {
 		panic(err)
 	}
+
 	return bz
 }