Fix smudging noise in trbfv_Pk

[zahrajavar]

Change e_sm: Polynomial<N> to e_sm: [Polynomial<N>; L] and fix the corresponding commitment.

[0xjei]

this results in a change of C2b circuit commitment because this was linked to C1's

[0xjei]

took the occasion to improve everything at commitment level

#1196
#72