Consider externalId in search criteria when using RecordRef as value

[cgunther]

Given a criteria like:

{
  field: 'company',
  operator: 'anyOf',
  value: [
    NetSuite::Records::RecordRef.new(external_id: "abc"),
    NetSuite::Records::RecordRef.new(external_id: "xyz"),
  ],
}

The gem was never passing that external ID to NetSuite for the result,
so you'd get a INVALID_KEY_OR_REF error as the XML line ended up
looking like:

<platformCore:searchValue xsi:type="platformCore:RecordRef" type="account"/>

Compared to the same line if you defined your RecordRef with an
internal ID:

<platformCore:searchValue internalId="1" xsi:type="platformCore:RecordRef" type="account"/>

Now that we pass the external ID too, that same line looks like:

<platformCore:searchValue externalId="abc" xsi:type="platformCore:RecordRef" type="account"/>

If your RecordRef has both internal and external IDs, it seems safe to
pass both and NetSuite seems to treat the internal ID as superseding the
external ID.

[iloveitaly]

As always, a great improvement! Thank you