[UIXPress] light/dark mode by default for users

Hello,

A simple idea: to be able to select the light or dark mode by default for users instead of following system preferences, or even for each user category, which they can modify themselves in all cases. This allows to offer an interface that comes immediately to a customer who prefers this or that mode, especially during the first connection. A bit in the same way as the selection of publication types in the search than the deactivation of the theme by user or user type.

It is not an important feature, but I would be happy if it comes. Thanks!