deployer() function should include principal type in result

**Is your feature request related to a problem? Please describe.**
Sometimes deployment (role assignment) stuck because ARM or Entra struggling to find the information about the principal (identity).
To avoid the issue, you should provide principalType.

**Describe the solution you'd like**
[deployer()](https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/bicep-functions-deployment) function should include principal type in result.

So it could be like
```json
{
"objectId": "",
"tenantId": "",
"type": "User"
}
```

Start with the deployer() function documentation linked in the issue and locate the implementation and tests for its returned object. Determine where the principal type would be sourced, then verify that the result includes a type value such as User alongside objectId and tenantId.

Written by the indexing model from the issue text.