fix(domain): use crypto.CryptoValue (#11131)

Update the `Check` struct to utilize `crypto.CryptoValue` for the `Code`
field, enhancing security and type safety. Adjust the `CheckTypeInit`
struct accordingly to maintain consistency.

backend/v3/domain/check.go

@@ -1,9 +1,13 @@
 package domain
 
-import "time"
+import (
+	"time"
+
+	"github.com/zitadel/zitadel/internal/crypto"
+)
 
 type Check struct {
-	Code           []byte     `db:"code"`
+	Code           *crypto.CryptoValue `db:"code"`
 	ExpiresAt      *time.Time          `db:"expires_at"`
 	FailedAttempts uint8               `db:"failed_attempts"`
 }
@@ -24,7 +28,7 @@ type CheckTypeInit struct {
 	// Expiry is the duration after which the check expires.
 	Expiry *time.Duration
 	// Code to be used for the check.
-	Code []byte
+	Code *crypto.CryptoValue
 }
 
 // isCheckType implements [CheckType].