Improve performance of Queues::drain_iter

[KonaeAkira]

Checking performance using the benchmark I added in #212 shows that performance has improved when compared to master:

time:   [250.53 µs 251.09 µs 251.69 µs]
change: [-1.8127% -1.3880% -1.0153%] (p = 0.00 < 0.05)
Performance has improved.

Godbolt: https://godbolt.org/z/f8W6v9fdo

[KonaeAkira]

The drop behavior of the new implementation is not the same as the old implementation, but that shouldn't matter as the iterator seems to never get dropped half-way.