* [Fused] LeakyRelu op

* Add LeakyRelu to serializer

* Add unit tests

* Fix merge branch 'master' into mkarzyns/fused_leaky_relu

* Change broadcasting rules to NumPy style

* Remove std:: and ngraph:: prefixes

* Rename CPU Runtime LeakyRelu to CPULeakyRelu

* Style apply

* Fix cpu_fusion.fuse_leaky_relu test

* Use eigen's tanh in the fused sigmoid multiply kernel (#2946)

* Merge branch 'master' into mkarzyns/fused_leaky_relu

* Add LeakyRelu to Intel GPU backend op list

* Add LeakyRelu to Intel GPU backend op list