Option to keep font-family case-sensitive

[TimoWilhelm]

Feature Request

Description

Satori seems to normalize all font names to lowercase which works great with most rendering engines.

I'm trying to use satori with svg2pdf to generate PDF files. I cannot embed the font as path to keep the PDF text selectable.
The issue is that it uses the fontdb library interally and unfortunately the fonts are not matched case-insensitive (RazrFalcon/fontdb#42).

Right now I need to add a step to go over the generated svg again and replace the font-family names with the original names.
It would be great to have an option to keep the casing for font-families intact.