When using default max result window value for size, we should account for offsets

[rebeccahum]

Description of the Change

Offset is not accounted for when assigning the default size below for comment queries:

ElasticPress/includes/classes/Indexable/Comment/Comment.php

Lines 75 to 81 in 4a2547e

	$number = apply_filters( 'ep_max_results_window', 10000 );
	}
	$formatted_args = [
	'from' => 0,
	'size' => $number,
	];

In not doing so, we could potentially hit the ep_max_results_window if an offset is passed in. Therefore, if we are using the default value for ep_max_results_window, we should account for the sum of offset and size being equal (or less than) the maximum results window.

From https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html:

index.max_result_window The maximum value of from + size for searches to this index. Defaults to 10000. Search requests take heap memory and time proportional to from + size and this limits that memory.

Alternate Designs

N/A.

Benefits

Possible Drawbacks

N/A.

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

Applicable Issues

Changelog Entry

Fixed: When using offset and default maximum result window value for size, subtract offset from size