Handle the points at infinity (∞)

[codygunton]

This is a tracking issue for our various issues relating to the point at infinity.

### Tasks
- [ ] https://github.com/AztecProtocol/barretenberg/issues/866
- [ ] https://github.com/AztecProtocol/barretenberg/issues/905
- [ ] https://github.com/AztecProtocol/barretenberg/issues/871
- [ ] https://github.com/AztecProtocol/aztec-packages/issues/2214
- [ ] https://github.com/AztecProtocol/barretenberg/issues/1100

[codygunton]

Whoops

[ledwards2225]

Letting the standalone issues stand on their own