User Accounts for AdGuardHome

Enhance AGHome as a multi-user system that handles multiple simultaneous active sessions with role of administrators and standard users.

Benefits
- Configure non-privilege users (view mode) to access query logs, dashboard and settings.
- Provide non-privilege access to certain device or range. https://github.com/AdguardTeam/AdGuardHome/issues/481
- Configure administrator access to certain 'IPs, CIDR, MACs' https://github.com/AdguardTeam/AdGuardHome/issues/809 for manage data and change settings (change DNS https://github.com/AdguardTeam/AdGuardHome/issues/821, filters https://github.com/AdguardTeam/AdGuardHome/issues/435 etc)
**_(this way we can keep provide 'Client' feature for such administrator)_**

_(Source: Ntopng)_

https://www.ntop.org/products/traffic-analysis/ntop/
https://github.com/ntop/ntopng

_Any other reasons?
To prevent implement https://github.com/AdguardTeam/AdGuardHome/issues/628_

---

Above mentioned user roles seems extend the development task too much due other adguardhome users various expectations then i prefer suggest to discard **user roles** and use **custom permissions** method with 'Client Settings' for user accounts.


1. Allowed networks - the range provide to certain user
(that user also able to create sub-accounts for someone else, it reduce the fever falls to server administrator)
2. Allow create accounts
(additional option but it helps to avoid unwanted users. ex: avoid kids, co-workers create accounts for strangers)
3. Use default settings
(if no intention to add clients then it helps to keep current account default settings rather than no protection but it still possible to override)
4. Lock button
(just lock all settings and we might need to use that individually for)
- each main settings - safe search, safe browsing, parental control
- each filter list - so we can prevent disable some filters
- dns servers tab
- blocked services tab

**Preference**
(this's an another column necessary to add next to 'main settings', 'block services', 'upstream servers')

- Access to Query Log https://github.com/AdguardTeam/AdGuardHome/issues/1326
- Access to Top queried/Blocked domains
- Access to DNS rewrites
- Access to Custom filtering rules
(also let access to block/ unblock domains)

**Filters**
(it's possible to keep that under client settings too, so we can add necessary filter lists) https://github.com/AdguardTeam/AdGuardHome/issues/435

Locked settings effect