storage: Call evaluateProposal only once

This method was previously called both before and after raft, and the
after-raft logic relied on fields that were set in the
ReplicatedProposalData by the before-raft logic. This caused
inconsistencies when cockroachdb#10327 was deployed without freeze-cluster.

Now, evaluateProposal is called only once, either before or after raft,
and the post-raft logic handles the command in whichever fashion is
appropriate for the version that proposed it.

Fixes cockroachdb#10602

pkg/cli/debug.go

@@ -424,7 +424,7 @@ func tryRaftLogEntry(kv engine.MVCCKeyValue) (string, error) {
 	if ent.Type == raftpb.EntryNormal {
 		if len(ent.Data) > 0 {
 			_, cmdData := storage.DecodeRaftCommand(ent.Data)
-			var cmd storagebase.ReplicatedProposalData
+			var cmd storagebase.RaftCommand
 			if err := cmd.Unmarshal(cmdData); err != nil {
 				return "", err
 			}

pkg/roachpb/string_test.go

@@ -62,7 +62,7 @@ func TestTransactionString(t *testing.T) {
 	var txnEmpty roachpb.Transaction
 	_ = txnEmpty.String() // prevent regression of NPE
 
-	cmd := storagebase.ReplicatedProposalData{
+	cmd := storagebase.RaftCommand{
 		Cmd: &roachpb.BatchRequest{},
 	}
 	cmd.Cmd.Txn = &txn

pkg/storage/raft.go

@@ -184,7 +184,7 @@ func raftEntryFormatter(data []byte) string {
 		// large snapshot entries.
 		return fmt.Sprintf("[%x] [%d]", commandID, len(data))
 	}
-	var cmd storagebase.ReplicatedProposalData
+	var cmd storagebase.RaftCommand
 	if err := proto.Unmarshal(encodedCmd, &cmd); err != nil {
 		return fmt.Sprintf("[error parsing entry: %s]", err)
 	}