[settings/object] fix export all button, searchType: scan is gone

[spalger]

Fixes #6414

[epixa]

What did searchType even do?

[spalger]

searchType: 'scan' used to be required for walking through a sorted set of documents in an efficient way but it was deprecated in 2.1 and is no longer needed (or supported). More info: https://www.elastic.co/guide/en/elasticsearch/reference/master/breaking_50_search_changes.html#_literal_search_type_scan_literal_removed

[epixa]

Does it make sense to also send sort:_doc then? That looks to be the recommendation from that BC doc page.

[bevacqua]

Ah. I thought it was still there, according to `elasticsearch-js: https://github.com/elastic/elasticsearch-js/blob/master/src/lib/apis/2_3.js#L5426-L5435

I suspected some mutability bug or something like that

Where is it gone from exactly?

[bevacqua]

LGTM

[bevacqua]

One comment I have here though, is that we should really handle the error.

Maybe:

if (error) {
  console.error(error);
  reject(error);
  return;
}

[w33ble]

This LGTM, based on the docs and the fact that I successfully exported 170 saved objects.