[PRCI - demo] ui enhancement - white background

[Clementinev]

As we talked at desko with Justin, in case we remove left menu #256, we could remove the grey background to have a white background (such as in sketches)gwe have right now:

Question about the footer "🖤 Made with love by blindnet with open-wc, Vaadin and Carbon Web Components."
Is the part "with open-wc, Vaadin and Carbon Web Components." mandatory ? Can we just keep the "🖤 Made with love by blindnet" and move it to the right ? So it is distinct from "Making a Privacy Request as clementine@blindnet.io. Change" if the whole background is white