Query and modify dconf settings with schema validation.
More information: <https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/using_the_desktop_environment_in_rhel_8/configuring-gnome-at-low-level_using-the-desktop-environment-in-rhel-8#using-gsettings-command_configuring-gnome-at-low-level>.