Cannot directly construct Pairing::G1 and Pairing::G1Affine

[vaqxai]

for g2 as well,
We can get x, y, z or x,y for the affine already,
why not have the option to create them manually (e.g. when calculating MSM or stuff like that externally?)
they're just numbers after all

concrete implementations like ark_bn254::G1Affine can be constructed directly, so why not have the Pairing also require methods to do so?

perhaps behind a feature to preserve backwards compatibility