Resource DeleteView uses package_delete auth function

[bzar]

CKAN version
2.9.6

Describe the bug
Allowing deleting resources but not packages is not possible, because

ckan/ckan/views/resource.py

Line 454 in 9f1b5cf

check_access(u'package_delete', context, {u'id': id})

checks package_delete.

Steps to reproduce
Steps to reproduce the behavior:

• Override package_delete and resource_delete auth functions with a plugin to create a situation where you can delete a resource in a package but not the package itsef
• Navigate to the resource's edit view
• Observe the delete button existing
• Try to delete the resource
• Observe 403 Forbidden: Unauthorized to delete package

Expected behavior
resource_delete auth function defining if a resource can be deleted

Additional details
Should be fixable by just changing the auth function. I'll make a PR.