Policy editor: access package improvements

[mgunnerud]

We should implement some improvements for access packages selection in policy editor:

• Show selected access packages with unknown urn (so users can remove these from the rule). Might be caused by typos or recent rename of some access package urns feat(policy-editor): Show unknown access packages if selected (to allow user to remove it) #15138
• Show resources connected to access package for both TT02 and Prod, not just Prod feat(policy-editor): show resources connected to access packages in both TT02 and prod #15128
• Add isDelegable field to access package. In the new metadata API, some access packages are not delegable, and the UI should not show these fix(policy-editor): add isDelegable field to access packages #15144
• Remove icon files for access packages. These are instead loaded directly from CDN fix(policy-editor): remove access package area icons #15140
• Remove unused properties in access package models refactor(policy-editor): remove unused fields from access package model #15161