Log error messages of the OcRestClient

[dennis531]

While debugging the plugin, we noticed that the ingestClient send no request to Opencast and didn't log a helpful error message. The problem is for example at

studip-opencast-plugin/lib/Models/REST/IngestClient.php

Lines 27 to 35 in 574680f

	public function createMediaPackage()
	{
	$response = $this->opencastApi->ingest->createMediaPackage();
	if (in_array($response['code'], [200, 201]) !== false) {
	return $response['body'];
	}
	return false;
	}

, where the client silently ignores the exception message from the OcRestClient, making debugging impossible.

The plugin should log exceptions for better debugging.