feat: blstrs backend and optimized proving

[dignifiedquire]

Uses https://github.com/dignifiedquire/blstrs to provide a pairing alternative backed by blst.
Also integrates the optimizations done in https://github.com/filecoin-project/fil-blst/

[arielgabizon]

Went over changes with @dignifiedquire and @porcuquine. Seem completely fine - a straightforward paralellization when possible of group operations.
There is a clash with the dummy engine implementation, but it has to do with the dummy engine using vector inner product as a miller loop, which is not really a miller loop - as it doesn't have the property in particular that e(ML(A,B)*ML(C,D)) = e(A,B)*e(C,D) where e is the pairing and ML is the miller loop.

[porcuquine]

Based on discussion with @arielgabizon and on @dignifiedquire's reversion of the change to the DummyEngine implementation, I approve. Let's create an issue to make sure we follow up with a clear fix to that test eventually.

[cryptonemo]

Is this CI failure an expected CI timeout where we could extend the test run time or a real bug holding up this work?

[porcuquine]

No, we need to sort out what is happening. I'm looking into it but don't have an answer or fix yet.