chore(path): improve code coverage and improve array path access

[pikax]

improve array access, now we can:

test("access with consecutive []", () => {
  const o = {
    a: {
      a: 1,
      b: [
        2,
        {
          c: {
            ["a-b-c-d"]: 3
          }
        }
      ]
    }
  };

  expect(usePath(o, "a[a]").value).toBe(o.a.a);
  expect(usePath(o, "[a]['a']").value).toBe(o.a.a);
  expect(usePath(o, '["a"][`b`][0]').value).toBe(o.a.b[0]);
  expect(usePath(o, "a.b[1].c[a-b-c-d]").value).toBe(
    o.a.b[1].c["a-b-c-d"]
  );
});