Lemur: Authenticated low-privilege users can read plaintext destination credentials (SFTP password / private-key passphrase) via the destinations API

Lemur manages TLS certificate creation. Prior to 1.9.3, GET /api/1/destinations and GET /api/1/destinations/ relied only on authentication while sibling write handlers required admin_permission. DestinationOutputSchema returned raw options and copied them into pluginOptions without redacting sensitive values. The sftp-destination plugin stored password and privateKeyPass values in plaintext, allowing even a read-only user to retrieve credentials for remote certificate-deployment hosts. The exposed credentials could permit direct access to SFTP systems and TLS material outside the Lemur security boundary. The fix requires administrator permission for destination reads and redacts options marked sensitive. This issue is fixed in version 1.9.3.