[eyedropper] Integrate automatic font-matching

[kptdobe]

The eyedropper simply capture the font name which in most of the cases is a non standard font.
On the production site, a default font is used until the font is loaded. In order to not break the CLS (Core Web Vitals...), you need to compute a default font setup that will not have an impact on the layout. This can be computed. Here is an example: https://www.industrialempathy.com/perfect-ish-font-fallback/?font=Montserrat (source is here https://github.com/googlefonts/cls_calculator)

We simply need to implement something similar and automatic to generate the proper a default font setup.