Add two-qubit rotation gates to Microsoft.Quantum.Intrinsic as fully supported APIs #1000

Currently the two qubit rotation gates IsingXX, IsingYY and IsingZZ are internal implementation details of the target package decompositions. However, they map to native hardware intrinsics on some platforms and can be reasonably decomposed in terms entanglers and single qubit rotations across other platforms. We should consider promoting them to full APIs and document them as part of the Microsoft.Quantum.Intrinsic namespace so that developers and library operations can make use them.