new images track for core logs & plugs

[fbosquet-azpn]

This is a draft PR to replace the other draft PR #83

Compare to the previous Pull request I have done the following:

• introduce a new photo-track in the videx-welllog code (previous PR was only a storybook class)
• use a real dataset of core images (free of used cf the README.md to see the origin and copyright) (previous PR was only refrencing to 200x200 pixels red and blue images.

Remaining issues:

• does not display properly when the trak is horizontal
• need speedup review.

Here is how it looks.
Nb: Yellow do are the Plugs (sample analysed in lab)