[Core] Make `-u` to allow operations on other user's resources instead of all users' resources

[Michaelvll]

Fixes #5994

Tested (run the relevant ones):

• [ ] Code formatting: install pre-commit (auto-check on commit) or bash format.sh
• [ ] Any manual or new tests for this PR (please specify below)
• [ ] All smoke tests: /smoke-test (CI) or pytest tests/test_smoke.py (local)
• [ ] Relevant individual tests: /smoke-test -k test_name (CI) or pytest tests/test_smoke.py::test_name (local)
• [ ] Backward compatibility: /quicktest-core (CI) or pytest tests/smoke_tests/test_backward_compat.py (local)