[feat] Implement OP_2, OP_3, ..., OP_16 opcodes

[b-j-roberts]

Implement the OP_X opcodes using the opcode_n function like OP_1 from shinigami

References

opcode_n Guide on how to add an opcode in shinigami

[hakymulla]

can i take this?

[onlydustapp[bot]]

Hey @hakymulla! Thanks for showing interest. We've created an application for you to contribute to shinigami. Go check it out on OnlyDust!

[ptisserand]

@b-j-roberts I need at least OP_2 to test implementation of OP_MIN #17 Is it ok if I add OP_{2..16} in the same PR ?

[b-j-roberts]

Thank ya'll for the rapid turn around on this issue! @ptisserand @hakymulla