Allow UltraHonk to handle public inputs

[ledwards2225]

Honk requires all polynomials for which we need a shift to have constant coefficient equal to zero. For standard Honk, the only polynomial that is shifted is the grand product, for which we enforce z[0] = 0. For UltraHonk we shift many more polynomials, including the wires. Since PI are placed at the beginning of the coefficient arrays, the constant coefficients will in general not be zero. A hack solution is to simply add 0 as the first PI in all circuits. A better solution may be to simply place the PI at the second position instead of the first, effectively leaving a row of zeros in the execution trace. More generally, we can define a public_inputs_offset specifying the shift the placement of the PI. For goblin, this value will be equal to the number of ecc op "gates" since these will live at the start of the execution trace.