Create app settings page

[edu-stx]

During the development of the theme switching feature (#2772) we settled for adding the theme switching prompt in the app's main menu. However, as the number of such settings grows, the menu will get crowded and will become harder to navigate.

In addition, we've started to discuss adding another feature, having a setting which allows users switch between having analytics on or off. As the number of settings grows, having them all in a dedicated space will make them easier to find and manage.

The theme setting, analytics, and other suggested settings would be available in the settings page.

We need to explore whether we have enough settings or have enough upcoming settings-related features to warrant the creation of a settings page, as well as some basic designs for it.