Use new JTable features for WeblinksTableWeblink

This method removes the overridden method for the publish method in favour of the table column alias introduced in https://github.com/joomla/joomla-cms/pull/3416

It also removes the override for the bind method in favour of the quicker method introduced in https://github.com/joomla/joomla-cms/pull/3423

## Testing
Test publishing a weblink in the list view works as expected (single and multiple items) and that saving an item works correctly (with things like associated images, params and metadata)