test(contrib/drivers/mysql): add pagination and error handling tests (gogf#4703)

## Summary
- Add comprehensive pagination tests (Limit, Offset, Page, ForPage)
- Add error handling tests for invalid operations
- Add tests for edge cases and boundary conditions

**Test coverage added:**
- Pagination: ~28 test functions
- Error handling: ~20 test functions

Ref gogf#4689

## Test plan
```bash
cd contrib/drivers/mysql
go test -v -run "TestModel_Pagination|TestModel_Error|TestModel_InvalidOperation"
```

Author: lingcoder