identity: simplify PublicKey interface

dbft package itself doesn't need anything from PublicKey. It's the user
who is responsible for public keys comparison and WithGetKeyPair
callback implementation.

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>

identity.go

@@ -6,10 +6,7 @@ import (
 
 type (
 	// PublicKey is a generic public key interface used by dbft.
-	PublicKey interface {
-		// Equals returns whether public key is equal to the other.
-		Equals(other PublicKey) bool
-	}
+	PublicKey any
 
 	// PrivateKey is a generic private key interface used by dbft.
 	PrivateKey interface {

internal/consensus/consensus.go

@@ -24,7 +24,7 @@ func New(logger *zap.Logger, key dbft.PrivateKey, pub dbft.PublicKey,
 		dbft.WithSecondsPerBlock[crypto.Uint256](time.Second*5),
 		dbft.WithGetKeyPair[crypto.Uint256](func(pubs []dbft.PublicKey) (int, dbft.PrivateKey, dbft.PublicKey) {
 			for i := range pubs {
-				if pub.Equals(pubs[i]) {
+				if pub.(*crypto.ECDSAPub).Equals(pubs[i]) {
 					return i, key, pub
 				}
 			}