Bugfix: Lazy loading render performance

The render performance of the lazy loading option in tables (OcTable, OcTableSimple) has been improved by removing the debounce option and by moving the lazy loading visualization from the OcTd to the OcTr component. For lazy loading, the colspan property has to be provided now.

https://github.com/owncloud/owncloud-design-system/pull/2260
https://github.com/owncloud/owncloud-design-system/pull/2266
https://github.com/owncloud/web/issues/7038
