moving decision on DCI format type to UE MAC
This MR moves the decision on the received DCI format to UE MAC based on format indicator bit. In case of formats 00 or 10 only one option is sent to L1 for decoding, since both options have the same size (size is the parameter that matters for L1 decoding, not format). The MR also splits the huge function to extract DCI information in smaller functions, depending on format and RNTI type.