[Afform] Do not replace multi record custom data on afform submit

[devdavc]

Overview

Fixes dev/core#5589
Multiple records custom field set is truncated or "replace" in Form Builder that has dedupe rules for contacts.

Comments

This is an attempt to fix this. Currently not sure if this is reliable. But the idea is to restrict replace on custom data multiple records. Maybe adding a flag to the custom group set might be a better solution, but for now this is the concept.

[civibot]

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[colemanw]

We want to propagate the $entityId into all records, not just the first one. APIv4 has a shorthand way of doing that:

Suggested change

	$values[0]["entity_id"] = $entityId;
	$result = civicrm_api4($joinEntityName, 'save', [
	$result = civicrm_api4($joinEntityName, 'save', [
	'defaults' = ['entity_id' => $entityId],

[colemanw]

Here's a WIP alternative: #31480