Azure Managed Redis - Access Policy Assignment - Enrich Assignment Data

### Preconditions

- [x] No need to upgrade Python SDK or the Python SDK is ready.

### Related command

az redisenterprise database access-policy-assignment list --resource-group {rg} --cluster-name {cluster} --database-name default

### Resource Provider

microsoft.cache/redisenterprise

### Description of Feature or Work Requested

The current output only shows the objectId. The output should include IdentityType (ServicePrincipal, Group, User, etc). Output should also include DisplayName and possibly UPN (for users).

Without this data, we have to manually expand permissions for our service principal accounts and write automation that will intelligently make decisions based on this basic, enriched data.

### Minimum API Version Required

2025-07-01

### Swagger PR link / SDK link

N/A

### Request Example

Response Body:
[
{
"properties": {
"accessPolicyName": "default",
"user": {
"objectId": "5a59f20f-d5f1-47c1-a571-b94af025a872",
"displayName": "First and Last Name",
"userPrincipalName": "first.last@company.com",
"identityType": "User",
},
"provisioningState": "Succeeded"
},
"id": "/subscriptions/117cc72c-bb3d-4b86-beba-be946bf2f5d8/resourceGroups/rxr-rxi-devqe-01-cus-rg/providers/Microsoft.Cache/redisEnterprise/rxr-rxi-devqe-cus-redis-goods-receiving-01/databases/default/accessPolicyAssignments/5a59f20f-d5f1-47c1-a571-b94af025a872",
"name": "5a59f20f-d5f1-47c1-a571-b94af025a872",
"type": "Microsoft.Cache/redisEnterprise/databases/accessPolicyAssignments"
},
]

### Target Date

2027-01-01

### PM Contact

@pm

### Engineer Contact

@engineer

### Additional context

_No response_