onRender event

Hi @paveljanda, @f3l1x

I have one question, I'm using DataGrid with Doctrine and in one specific case, can not use QueryBuilder and I'm sending data to DataGrid like bellow

$grid->setDataSource($em->getConnection()->fetchAll('my query'));

So, problem is, when I use inline edit, because after edit the row, changes not redraw.

I'm using workaround, than first set empty QueryBuilder and on event onRender set real DataSource, look below

$grid->setDataSource($em->createQueryBuilder());

$grid->onRender[] = function (\Ublaboo\DataGrid\DataGrid $grid): void {
	$grid->setDataSource($em->getConnection()->fetchAll('my query');
};

This is very ugly and not clear, so what you thing about PR, where move call onRender events on start of render method or added new callback with name onBeforeRender?

Start by locating DataGrid's render method and the existing onRender event handling mentioned in the issue. Compare the proposed event-timing change with the alternative onBeforeRender callback, then define the expected lifecycle and verify that inline edits using fetchAll data redraw correctly.