Add `WithEncryption` option that passes ECDSA key to the persistent session storage. It uses 32 bytes from marshalled ECDSA key in ASN.1 DER from in AES-256 algorithm encryption in Galois/Counter Mode. Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>