Added functions to Arithmetic namespace (and more)

[DmitryVasilevsky]

• Added Microsoft.Quantum.Arithmetic namespace.
• Added ApplyXorInPlace, AddI, RippleCarryAdderNoCarryTTK, and RippleCarryAdderTTK to Arithmetic namespace with some modifications. These are operations used in Shor and are generally useful for arithmetic oracles.
• Added operation ApplyCNOTChain with some modifications to Canon namespace (it used to be in that namespace).
• Added functions InverseModI, InverseModL, ContinuedFractionConvergentI with some modifications to Math namespace.
• Tests.