Move more from \OC to PSR-4

* \OC\OCSClient
* \OC\Preview
* \OC\PreviewManager
* \OC\Repair
* \OC\RepairException
* \OC\Search
* \OC\ServerContainer
* \OC\ServerNotAvailableException
* \OC\ServiceUnavailableException
* \OC\Setup
* \OC\Streamer
* \OC\SubAdmin
* \OC\SystemConfig
* \OC\TagManager
* \OC\Tags
* \OC\TempManager
* \OC\TemplateLayout
* \OC\URLGenerator
* \OC\Updater