add: IPA Proof and Multiproof Ser/De

[agnxsh]

Fixes #349

IPA Proofs in Verkle consists of

1. a Left array of 8 Base Field points, a Right array of 8 Base Field points,

2. and a Scalar Field element.

During serialization the format goes as follows:

L[0] (32 - byte array) L[1] (32 - byte array) .... L[7] (32 - byte array) ..... R[0] (32 - byte array) ... R[7] (32 - byte array) A (32 - byte array)

Which means the size of the byte array should be :

32 * 8 (for Left half) + 32 * 8 (for Right half) + 32 * 1 (for Scalar) = 32 * 17 = 544 elements in the byte array.

• Note that checks like Subgroup check for Banderwagon Points for Base Field elements in L and R, and checks for a valid scalar checking the Banderwagon Curve Order is mandatory. They are all checked in the further low level functions

• Note that check for Lexicographically Largest criteria for the Y - coordinate of the Twisted Edward Banderwagon point is also mandatory and, is pre-checked within this function from the deserialize function.

Multiproofs in Verkle have a format of

1. The queried Base Field where the Vector Commitment opening is created, consider this as the equivalent to the Merkle Path in usual Merkle Trees.

2. The entire IPAProof which is exactly a 576 byte array, go through serializeIPAProof for the breakdown

The format of serialization is as:

Query Point (32 - byte array) .... IPAProof (544 - byte array) = 32 + 544 = 576 elements in the byte array

[mratsim]

Thanks!