treewide: use new gluon.site Lua library

...gluon-mesh-vpn-core/luasrc/lib/gluon/upgrade/500-mesh-vpn

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

...digger/luasrc/lib/gluon/upgrade/400-mesh-vpn-tunneldigger

...uon-node-info/luasrc/lib/gluon/upgrade/510-node-info-role

...uon-setup-mode/files/lib/gluon/setup-mode/rc.d/S20network

.../gluon-setup-mode/luasrc/lib/gluon/upgrade/300-setup-mode

.../gluon-web-admin/files/lib/gluon/web/view/admin/info.html

...fastd/luasrc/lib/gluon/web/model/admin/mesh_vpn_fastd.lua

...b-node-role/luasrc/lib/gluon/web/model/admin/noderole.lua