rewrite test helper

[ricardoV94]

This PR adds a helper to streamline our rewrite tests, according to what I these days feel is the best strategy:

1. Write a graph
2. Rewrite
3. Check the rewrite matches what we expect
4. Eval both original and rewritten without any extra compilation

For instance, the test in #2101 would look like:

@pytest.mark.parametrize("b_ndim", [1, 2], ids=lambda x: f"b_ndim={x}")
def test_solve_of_inv_to_matmul(b_ndim):
    X = pt.dmatrix("X")
    b = pt.dvector("b") if b_ndim == 1 else pt.dmatrix("b")

    out = solve(pt.linalg.inv(X), b, b_ndim=b_ndim)

    result = utt.rewrite_test([X, b], [out])
    result.assert_equivalent_computations([pt.dot(X, b)])

    rng = np.random.default_rng(42)
    X_val = rng.random((4, 4)) + np.eye(4) * 4
    b_val = rng.random((4,) if b_ndim == 1 else (4, 3))
    result.assert_numerical_close([X_val, b_val], rtol=1e-6)

I really don't like op counts, because it can miss stuff like AdvancedSubtensor become AdvancedSubtensor1, or Blockwise(Dot) become Dot, or Gemm, and it seems like we are optimizing stuff when we are not. Still I added the helpers to count ops...

The main goal though is to reduce friction / have a baseline for contributions