New CLI admin tool

[syzop]

I think it would be a good idea to have a command line (CLI) tool, like most webprojects have, for management of the panel itself. Like mediawiki has a maintenance/ directory for that (not a fan), NextCloud has the 'occ' command (better), etc.
Some commands would overlap with the normal webinterface, for example upgrading or installing a plugin would be possible both from the webpanel itself and on the command line (CLI). The CLI would then only be used if, for example, the admin set strict file permissions making the webinterface way impossible (webuser having no write access to the directory).
Other commands could be handy if you have access problems. For example I think a way to reset a password for a user account on the command line would be useful if people locked themselves out, so they don't need to reinstall (yeah I'm sure there is or will be a reset password option via email as well, but still...).

I'm talking about a very limited of commands here, that use the same code interface behind the curtains.