feat: backup previous password, change password via personal data form

tests/Security/BpnAuthenticatorTest.php

@@ -155,6 +155,7 @@ class BpnAuthenticatorTest extends TestCase
         $passport = $authenticator->authenticate($this->createRequest('[email protected]', 'secret'));
 
         self::assertInstanceOf(SelfValidatingPassport::class, $passport);
+        self::assertSame(base64_encode('legacy-ciphertext'), $user->getPreviousPassword());
         self::assertSame('local-hash', $user->getPassword());
         self::assertSame(123, $user->getAddressId());
         self::assertSame(456, $user->getPersonId());