ipaconfig: Do not require enable_sid for add_sids or netbios_name

Current behavior of ipaconfig mimics FreeIPA CLI and requires that
'enable_sid' is set to True every time add_sids or netbios_name are
used. It is sufficient that SID generation is enabled to use add_sids
and netbios_name, but the IPA API requires 'enable_sid' so that the
operations are executed.

This patch allows ansible-freeipa plugin ipaconfig to run 'add_sids' or
set 'netbios_name without requiring 'enable_sid' to be set on the
playbook.

If SID generation is enabled, 'add_sids' and 'netbios_name' can be used
without 'enable_sid: yes'. If SID generation is not enabled, an error
message will be raised if 'enable_sid: yes' is not used.