Ticket #47677 - Size returned by slapi_entry_size is not accurate
    
    Description: slapi_entry_size calculating the entry size had issues.
    . To calculate the Slapi_DN size, local function slapi_dn_size was used.
      Local slapi_dn_size missed to count the raw dn length.  This patch
      replaces slapi_dn_size with (slapi_sdn_get_size - sizeof(Slapi_DN)).
    . slapi_entry_size counted Slapi_RDN twice.
    . slapi_entry_size did not count the size of e_virtual_lock, e_aux_attrs
      and e_extension.
    
    https://fedorahosted.org/389/ticket/47677
    
    Reviewed by rmeggins@redhat.com (Thank you, Rich!!)
    (cherry picked from commit b1e4cdf5131a1730c9d3674b19d0e2a0670286e7)