NetQIR specification

NetQIR is an intermediate representation for distributed systems. It is born from QIR, the intermediate representation for monolithic quantum computing. This specification aims to show the added functionalities employed on top of the ones already implemented by QIR. This means that NetQIR does not aim to replace QIR, but to extend it, similar as MPI extends C. Our ultimate goal is to have a proper intermediate representation for distributed quantum systems.