Fix ssscpac/chat-locker#14.  Update ldap import to set name field using ldap's givenName and sn fields.
Fix ssscpac/chat-locker#14.  Update ldap import to set name field using
ldap's givenName and sn fields.

- Replaced confusing field mapping with functions that directly convert an
  LDAP entry to an Rocket.Chat user object.
- Set name field to use ldap's given name and sn fields, and also set in
  profile.first_name and profile.last_name to aid in search by first or
  last name.

sscpac/chat-locker,sscpac/chat-locker,sscpac/chat-locker