feat: add organization details to audit log response (#13961)

* Allow creating test audits with nil org

Not all audit entries have organization IDs, so this will allow us to
test those cases.

* Add organization details to audit log queries

* Add organization to audit log response

This replaces the old ID.  This is a breaking change but organizations
were not being used before.

docs/api/audit.md

@@ -47,6 +47,12 @@ curl -X GET http://coder-server:8080/api/v2/audit?limit=0 \
       "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
       "ip": "string",
       "is_deleted": true,
+      "organization": {
+        "display_name": "string",
+        "icon": "string",
+        "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
+        "name": "string"
+      },
       "organization_id": "7c60d51f-b44e-4682-87d6-449835ea4de6",
       "request_id": "266ea41d-adf5-480b-af50-15b940c2b846",
       "resource_icon": "string",