Non-exhaustive LDAP structs

[ancwrd1]

Most of the top-level rasn-ldap structs are declared with non-exhaustive attribute which prevents them from being constructed outside of the rasn-ldap crate.
How is the LdapMessage supposed to be constructed for encoding?

[XAMPPRocky]

Thank you for your issue! Yeah, it's a bit of an annoying situation at the moment. The correct solution would probably be to add constructors for the types with just the required arguments. Though it's a bit of boilerplate work so I won't be able to add it immediately. If you (or someone else) wants to make a PR adding it I would accept it.