Use an optimizer for PureScript output

[toastal]

https://github.com/aristanetworks/purescript-backend-optimizer

Code size and performance improvement varies by usecase, but we've generally observed:

• 25-35% improvement in runtime.
• 20-25% improvement in minified bundle size.
• 15-20% improvement in minified+gzip bundle size.

I'm not entirely sure if this supplants Zephyr or not, bundle size and performance aren't going to match most production PureScript project who will be running an optimizer.

If those stats are to be believed, we would expect

Implementation	Generated code size (bytes)	Average time of 4142 instructions (ms)
JavaScript	12,877	0.98
PureScript (opt)	113,652 - 121,229	89.05 - 102.75
PureScript	151,536	137.03

This would not improve standings, but might be closer to "real world".