Force PDF viewer to use dark mode or light mode regardless of browser mode

Hi,

Currently the PDF viewer takes the color of the theme set in the browser: if it is set to dark mode, it uses the dark mode; if it is set to light mode, it uses light mode.

However, sometimes it is interesting that the PDF viewer does not take the color of the theme set in the browser, since our web theme may not match it visually.

For this reason, I wanted to request that a new configuration option be created in the Gutenberg block that allows you to set the default mode or color that the PDF viewer will use: dark mode or light mode, regardless of the color established in the browser theme.

Regards.