Update pipeline to consider missing channels

Currently the steps 'referencing' and 'region identification' take two main files: the edf file and the SEEGA.tsv with the channels' location. The rereferencing step builds the bipolar channels only based on the SEEG.tsv file and then it tries to build the bipolar signal by looking at them in the edf file; however, not all the channels from the tsv are always in the edf file. Then, it's necessary to check which labels are in the edf and the tsv. Also, as there might be contacts missing, it's necessary to filter the bipolar combination so that no bipolar channels are created between far away electrodes.

mcespedes99 / sEEGPrep

Update pipeline to consider missing channels #14