ElementController::getRequest() returns a NullHTTPRequest

[kinglozzer]

Workaround is to use $request = Injector::inst()->get(HTTPRequest::class). We should probably pass that global request instance through when we create the controller here:

silverstripe-elemental/src/Models/BaseElement.php

Lines 463 to 464 in db9650c

	$this->controller = Injector::inst()->create($controllerClass, $this);
	$this->controller->doInit();