Further optimized SWAP into sqiswap

[evmckinney9]

Inside of OptimizedSqiswapSub

# XXX we think these can go away if have a perfect decomposition, but hard to find with our approx methods
PERFECTED_DECOMP_SWAP = False
# add random 1Q gates
if not PERFECTED_DECOMP_SWAP:
    sub_qc.u(np.random.random(), np.random.random(), np.random.random(), 0)
    sub_qc.u(np.random.random(), np.random.random(), np.random.random(), 1)

Nearing high-fidelity, but not quite without this additional internal layer: