[Improvement] make Jcasbin enforcer stateless

### What would you like to be improved?

Currently we keep all Gravitino privileges in Jcasbin enforcer, and use a event system to keep consistent the privilege with Gravitino entity store. There are some cons:
1. The Jcasbin enforcer information are not syced in multi Gravitino server enviroments.
2. It is hard to maintain the correctness of the privilege by event
3. In a concurrent environment, could it work well?

### How should we improve?

Create a new `enforcer` for each authorizer request, maybe an extra performance decrease for creating `enforcer` object.

Start by tracing the authorizer request path and how the Jcasbin enforcer is synchronized with the Gravitino entity store through the event system. Examine the current privilege handling and assess the proposed per-request enforcer against concurrent and multi-server use. Done means privilege state no longer depends on shared enforcer synchronization and remains consistent across Gravitino servers.

Written by the indexing model from the issue text.