FIX: Align random.draw size dispatch for numpy integers

[kocaemre]

Closes #918.

Summary

• Treat numpy integer sizes (for example np.int64(10)) the same as Python int in the pure-Python random.draw path.
• Keep boolean size values on the scalar branch so Python and jitted dispatch agree.
• Add focused regression tests covering Python and @njit callers for both cases.

Test plan

• RED: pytest quantecon/random/tests/test_utilities.py::TestDraw::test_numpy_integer_size_returns_array quantecon/random/tests/test_utilities.py::TestDraw::test_bool_size_is_treated_as_scalar -q failed with the Python path returning a scalar for np.int64(10) and raising TypeError for True.
• GREEN: same focused command passed: 2 passed in 6.43s.
• pytest quantecon/random/tests/test_utilities.py -q — 11 passed in 4.45s.
• pytest quantecon/random -q — 11 passed in 4.54s.
• pytest quantecon -q — 602 passed, 2 warnings in 504.77s.
• flake8 --select=F401,F405,E231 quantecon.
• git diff --check.