Debug mode for VideoAnalysis section, to tune sensitivity
**Is your feature request related to a problem? Please describe.**
It’s difficult to fine tune the sensitivity of the VideoAnalysis motion sensor. 

**Describe the solution you'd like**
Provide a debug log of the % of image change in each frame, that we can rely to set the Sensitivity afterwards. This debug could be an optional parameter of VideoAnalysys section. 

**Describe alternatives you've considered**
Take a very long time to adjust sensitivity of each Camera…
