Refactor elliptic curve API

[querolita]

          That would require a bigger change, but I would have used a more explicit name to understand which form of curve and which coordinates we're using.

createCurve -> createWeierstrassAffineCurve
createCurveTwisted -> createTwistedEdwardsAffineCurve

The space (i.e. affine vs projective) could be omitted as most of the time, in circuit, we use the affine coordinates.

Originally posted by @dannywillems in #1949 (comment)