perf: Consider faster batch forgery identification

[Yawning]

Right now, the strategy used for batch verification with forgery identification is to fall back to serial verification. Per "Faster batch fogery identification", it is possible to reuse intermediaries from the multiscalar multiply when identifying the forgeries.

Complications:

• The experimental results with Stratus has a cutoff of n/3 forgeries beyond which, serial verification is faster.
• We use Pippenger for large batches.