BM_sim_QCBM taxes Qrack's use of on-chip RNG

[WrathfulSpatula]

I already have a fix, but the BM_sim_QCBM test currently uses Qrack's simulator random number generator for random rotation angles. This happens to be enough RNG demand to empty the on-chip entropy pool. I'm converting this to use a pseudo-RNG, like the QuEST suite, and I'll add it in #53.

[WrathfulSpatula]

(Fixed in #53)