* DynSlice was adjusted to specyfication

* Fixed documentation

* Fixed styles

* Fixed clang warning

* Introduced StridedSlice as separate op

* revert dyn_slice

* Fixed StrideSlice implementation

* Enable downgrade pass in dynamic backend

* Implemented upgrade/downgrade pass

* Added serialization

* Styles applied

* Styles applied. Part.2

* Updated dynamic backends list

* Move StridedSlice outside experimental

* Make Slice as v0 of StridedSlice

* Styles applied

* Styles applied

* Fixed clang error

* Code review remarks introduced

* Move GenerateMask up in Opset0Downgrade to keep alphabetical sort

* Style apply