Views display_id not in contextual link fragment

When you create a field view and use it as a block in your site, the contextual views edit link does link to the correct view, but does not include the #fragment for the display_id.

The reason is that the code for fetching the display_id is dependent on the $object being a view, not a block:

if ($display_id = $object->display_handler->display->id) { ...

Attached patch fetches the view display_id conditionally from either $object being a view object or $object being a block (where the display_id is part of the block's delta).

Somewhat related to #931286: Working views integration