* validate_and_infer_types() implementation
* input parameter validation for LSTM, GRU and RNN
* style-check applied
* Add LSTMSequence dynamic shape validation and test props for RNNCell, GRUCell, LSTMCell and LSTMSequence.
* recurrent_sequence.hpp moved to ngraph/core/include/ngraph/op/util/
* style check applied
* removed unused variable from LSTMSequence::validate_and_infer_types
* Add missing newline mark at the end of file.
* Add supression macro for FusedOp deprecation.
* Add element type initialization
* Apply PR review remarks
* Rewrite tests to use gtest exception assertions.