Dry-run for LDAP/AD sync

[t-aleksander]

We could probably perform some validation of user provided values, as currently they need to basically guess if the synchronization works correctly. A dry-run option could be provided at least.

[Va1ter]

@t-aleksander https://www.figma.com/design/dZgIk8Ph3EXT0pGfH51MAW/Core?node-id=6085-53593&t=3S1C5hcIOD3QhsMs-11