cvxif_VP.xlsx: update the cvxif Verif Plan

Created by: ZElkacimi

Following the reviews in the issue #1192 , and as lot of work on the CVXIF verification have been done since the last published verifplan. This version includes:

• the suggested points on the review
• the link of implemented coverage
• a presentation sheet
• update the instruction sheet
• separate Protocol-specific from Integration-specific

I mentioned only the main points to facilate the tracking of the modifcations. Yet, the review needs to go through the whole file.