libs/common: Refactor libs/common 4 (#4237)

* libs/common: Refactor libs/common 4

- move byte function out of cmn to its own pkg
- move tempfile out of cmn to its own pkg
- move throttletimer to its own pkg

ref #4147

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* add changelog entry

* fix linting issues

types/vote.go

@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"github.com/tendermint/tendermint/crypto"
-	cmn "github.com/tendermint/tendermint/libs/common"
+	tmbytes "github.com/tendermint/tendermint/libs/bytes"
 )
 
 const (
@@ -110,13 +110,13 @@ func (vote *Vote) String() string {
 
 	return fmt.Sprintf("Vote{%v:%X %v/%02d/%v(%v) %X %X @ %s}",
 		vote.ValidatorIndex,
-		cmn.Fingerprint(vote.ValidatorAddress),
+		tmbytes.Fingerprint(vote.ValidatorAddress),
 		vote.Height,
 		vote.Round,
 		vote.Type,
 		typeString,
-		cmn.Fingerprint(vote.BlockID.Hash),
-		cmn.Fingerprint(vote.Signature),
+		tmbytes.Fingerprint(vote.BlockID.Hash),
+		tmbytes.Fingerprint(vote.Signature),
 		CanonicalTime(vote.Timestamp),
 	)
 }