treewide: get rid of luci.util outside of config mode/advanced settings

.../luasrc/lib/gluon/upgrade/300-gluon-client-bridge-network

package/gluon-core/luasrc/lib/gluon/upgrade/010-primary-mac

...age/gluon-core/luasrc/lib/gluon/upgrade/220-interface-lan

package/gluon-core/luasrc/lib/gluon/upgrade/500-opkg

package/gluon-core/luasrc/lib/gluon/upgrade/999-version

package/gluon-core/luasrc/usr/lib/lua/gluon/platform.lua

package/gluon-core/luasrc/usr/lib/lua/gluon/util.lua

...ig/luasrc/usr/lib/lua/luci/model/cbi/admin/portconfig.lua

...esh-vpn-fastd/luasrc/lib/gluon/upgrade/400-mesh-vpn-fastd

...info/files/lib/gluon/upgrade/520-node-info-whitespace-fix

...e-api/luasrc/lib/gluon/status-page/www/cgi-bin/interfaces