ZK sumcheck when having random values at the start of polynomials

[maramihali]

Currently, ZK sumcheck is implemented to expect a random contribution at the end of polynomials. In the case of translator, this contribution will exist both at the beginning and end of sumcheck.

[iakovenkos]

To save some work: It can be extracted from my commits related to ZK Sumcheck impl, pls ping me when relevant and I can find it

[ledwards2225]

We're handling this at the level of relations not sumcheck