[feature] nao package manager enhancements

[raisjn]

• ~~integrate into remux (add a new button in bottom of remux that launches nao)~~
• ~~alternatively, add a draft config for nao~~
• add ability to turn on and off repositories in nao (with some preopulated repos)
• add check for network to nao and if network isn't available, make it known
• ~~capture stderr when running commands (not just stdout) and display it~~
• show install / uninstall button only when relevant in package display scene
• add button to show only installed / uninstalled packages to package listing page
• ~~add button to run opkg update (update the package repo)~~
• ~~add button to run opkg upgrade (upgrade all installed packages)~~
• add button to add toltec repositories to opkg.conf

[raisjn]

• add ability to switch toltec branches