SSZ Multiproof

[ec2]

TODO:
[x] Clean up some duplicate code
[x] Consider removing some of the preprocessor tests which only test individual circuits
[x] Fix spec tests

This PR reduces the amount of advice cells being used. We merklize a whole beacon header in circuit when what we really want is just a merkle proof for a couple specific fields.
Before:

read params from ./params/kzg_bn254_21.srs
Gate Chip | Phase 0: 11535114 advice cells
Total 2059 fixed cells
Total range check advice cells to lookup per phase: [1222736, 0, 0]
Gate Chip | Phase 0: 1599532 advice cells
Total 1795 fixed cells
Total range check advice cells to lookup per phase: [4096, 0, 0]
test tests::test_both_circuit_sepolia has been running for over 60 seconds
test tests::test_both_circuit_sepolia ... ok

After:

read params from ./params/kzg_bn254_21.srs
Gate Chip | Phase 0: 11182651 advice cells
Total 2035 fixed cells
Total range check advice cells to lookup per phase: [1188896, 0, 0]
Gate Chip | Phase 0: 1598616 advice cells
Total 1767 fixed cells
Total range check advice cells to lookup per phase: [4096, 0, 0]

[nulltea]

we have this in 5 or more places now (incl step circuit), might be worth putting this in a util method for this?

[ec2]

I've removed the patch to halo2curves in the PR as well :D

[nulltea]

My point re. code repetition still stands. Otherwise LGMT