Fix #5513 - Can't delete blog post drafts

Fix #5513 - Can't delete blog post drafts

Modify the @get_media_entry_by_id decorator to return media regardless
of processing state. Separately modify all view functions that use the
@get_media_entry_by_id decorator to require that the media be in the
processed state, other than for the media_confirm_delete view. This
allows blog post drafts to be deleted without returning a 404. Further,
it adds the ability to delete unprocessed media in the future, which
would be a nice addition to the user processing panel.