[8.x] Fixed aggregates (e.g.: withExists) for one of many relationships

[cbl]

This pr fixes aggregates like withExists when used for one of many relationships (#37362).

The problem was that the join clause was passed to the existence query, but not the bindings.

The joins are now added included bindings in the following method:

framework/src/Illuminate/Database/Eloquent/Relations/Concerns/CanBeOneOfMany.php

Lines 192 to 197 in 3baf475

	protected function mergeJoinsTo(Builder $query)
	{
	$query->getQuery()->joins = $this->query->getQuery()->joins;
	$query->addBinding($this->query->getBindings(), 'join');
	}

Used here in HasOne:

framework/src/Illuminate/Database/Eloquent/Relations/HasOne.php

Lines 71 to 78 in 3baf475

	public function getRelationExistenceQuery(Builder $query, Builder $parentQuery, $columns = ['*'])
	{
	if ($this->isOneOfMany()) {
	$this->mergeJoinsTo($query);
	}
	return parent::getRelationExistenceQuery($query, $parentQuery, $columns);
	}

And MorphOne:

framework/src/Illuminate/Database/Eloquent/Relations/MorphOne.php

Lines 69 to 76 in 3baf475

	public function getRelationExistenceQuery(Builder $query, Builder $parentQuery, $columns = ['*'])
	{
	if ($this->isOneOfMany()) {
	$this->mergeJoinsTo($query);
	}
	return parent::getRelationExistenceQuery($query, $parentQuery, $columns);
	}