Register proto key parsers and serializers for ED25519

As a consequence, all ED25519 keys in a keyset are now parsed as `ed25519.{Private,Public}Key`s. Parsing of invalid private/public keys will fail.

PiperOrigin-RevId: 673417211
Change-Id: I8fcc71d007617a5ce8f6b3c8859f204319e2903b

signature/ed25519/ed25519.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/tink-crypto/tink-go/v2/core/registry"
 	"github.com/tink-crypto/tink-go/v2/internal/internalregistry"
+	"github.com/tink-crypto/tink-go/v2/internal/protoserialization"
 )
 
 func init() {
@@ -33,4 +34,16 @@ func init() {
 	if err := registry.RegisterKeyManager(new(verifierKeyManager)); err != nil {
 		panic(fmt.Sprintf("ed25519.init() failed: %v", err))
 	}
+	if err := protoserialization.RegisterKeySerializer[*PublicKey](&publicKeySerializer{}); err != nil {
+		panic(fmt.Sprintf("ed25519.init() failed: %v", err))
+	}
+	if err := protoserialization.RegisterKeyParser(verifierTypeURL, &publicKeyParser{}); err != nil {
+		panic(fmt.Sprintf("ed25519.init() failed: %v", err))
+	}
+	if err := protoserialization.RegisterKeySerializer[*PrivateKey](&privateKeySerializer{}); err != nil {
+		panic(fmt.Sprintf("ed25519.init() failed: %v", err))
+	}
+	if err := protoserialization.RegisterKeyParser(signerTypeURL, &privateKeyParser{}); err != nil {
+		panic(fmt.Sprintf("ed25519.init() failed: %v", err))
+	}
 }