use the degree as parameter to the benchmarks (dragoon/komodo!66)

... instead of the number of bytes that does not really make any sense because we only consider one polynomial, i.e. only one column / shard of data.

the following relation between the degree of the polynomials and the size of the data holds still
$$\text{deg}(P) = \frac{\#\text{bytes}}{k \times |f_r|}$$ where $|f_r|$ is the size of an element of the scalar finite prime field of the elliptic curve $F_r$ and $P$ is the polynomial of a single column / shard of data