Remove old benchmark tests and add new ported tests from Go Casbin

- Removed all existing jCasbin benchmark tests
- Created EnforcerBenchmarkTest.java (ported from model_b_test.go)
- Created CachedEnforcerBenchmarkTest.java (ported from enforcer_cached_b_test.go)
- Created ManagementApiBenchmarkTest.java (ported from management_api_b_test.go)
- Created RoleManagerBenchmarkTest.java (ported from role_manager_b_test.go)
- All tests follow JMH benchmark structure and compile successfully

Co-authored-by: hsluoyz <3787410+hsluoyz@users.noreply.github.com>

Author: Copilot