refactor(account-management): Separate group views from internal views

[susnux]

• Resolves Weird URL for accounts -> recently active #46776

Summary

Some refactoring of the route handling for the account management. We separate internal views like disabled or recent accounts from group views like admin or custom-group-id.

The new URL looks like:
/settings/users/VIEW(/GROUP) for example a real group like admin has this new URL: /settings/users/group/admin.
While internal views like recent users look like: /settings/users/recent.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[kesselb]

Thanks for picking it up 🙏

1. I've run into an issue with the password confirmation modal. Tip: Change nc_lastLogin to 0 in JSConfigHelper.php to always see the password confirmation request.

2. Probably out of scope, but if you create a group called "disabled", then the group is still not visible, but the disabled section is also gone 🤷

[susnux]

@kesselb

1. is unrelated - best report this in https://github.com/nextcloud-libraries/nextcloud-password-confirmation/issues
2. this one I would fix here. Lets see whats going on there.