feat: Bug fixing + tests

[Fitznik]

Cover exception cases:

• G1 infinity point, the result should be zero, and the point should be masked
• G2 infinity point, the result should be zero, and the point should be masked
• G1 and G2 are not on the curve; the result should be masked, but success should be true

Fixed bugs:

• bug in subgroup check
• bug in Oracle
• Pairing did not correctly handle infinity points

[koloz193]

CI is failing but code looks good to me