[Tagging] Use object permissions in frontend #160

"As a content author, I want the UI to show me when I can add/update/delete a taxonomy or tag and when I cannot, rather than waiting for a backend error, so that I can easily manage my taxonomies and tags."

Acceptance Criteria

1. Update the taxonomy, tag, and object tag REST APIs to return a consistent user_permissions record with each object returned by the API, e.g.

   {
    "next": null,
    "previous": null,
    "count": 8,
    "num_pages": 1,
    "current_page": 1,
    "start": 0,
    "results": [
      {
        "id": 2,
        "name": "ESDC Skills and Competencies",
        "description": "Employment and Social Development Canada - Skills and Competencies Taxonomy (EN) 2023 Version 1.0. Licence: Open Government Licence - Canada",
        "enabled": true,
        "allow_multiple": true,
        "allow_free_text": false,
        "system_defined": false,
        "visible_to_authors": true,
        "tags_count": 423,
        "orgs": [],
        "all_orgs": true,
        "user_permissions": {
              "oel_tagging.add_taxonomy": true,
              "oel_tagging.view_taxonomy": true,
              "oel_tagging.change_taxonomy": true,
              "oel_tagging.delete_taxonomy": true,
        },
     },
     {
        "id": 6,
        "name": "FlatTaxonomy",
        "description": "A simple, flat taxonomy used by SampleTaxonomyOrg1",
        "enabled": true,
        "allow_multiple": true,
        "allow_free_text": false,
        "system_defined": false,
        "visible_to_authors": true,
        "tags_count": 5000,
        "orgs": ["SampleTaxonomyOrg1"],
        "all_orgs": false,
      },
      "user_permissions": {
              "oel_tagging.add_taxonomy": true,
              "oel_tagging.view_taxonomy": true,
              "oel_tagging.change_taxonomy": false,
              "oel_tagging.delete_taxonomy": false,
        },
     ...
     ],
   }
   

2. Update the frontend-app-course-authoring UI to use these user_permissions to determine whether to show/enable the "Import", "Re-import" and "Delete" menu actions for a given taxonomy.

3. (if done after [Tagging] Rename an individual tag #131 / [Tagging] Add tags to a taxonomy #132) Update the frontend-app-course-authoring UI to use these user_permissions to determine whether to show/enable the "Add", "Rename" and "Delete" menu actions for a given tag.

Developer notes

1. Edge case: When no "taxonomies" are returned by the REST API for a given user, then we aren't able to see whether that user has oel_tagging.add_taxonomy permission. So in this case, go ahead and show the "Import" button and allow the user to try the import, and let the backend enforce the rule.