[feature request] Add possibility to configure dependencies between monitors

Possibility to configure dependencies between monitors.
Example:
```mermaid
graph TD
A[Proxmox Host] --> B[VM 101 - Web]
A[Proxmox Host] --> C[VM 102 - DB]
A[Proxmox Host] --> D[VM 103 - Fileserver]
A[Proxmox Host] --> E[VM 104 - Dev Host]

B --> B1[Apache/Nginx]
C --> C1[MySQL/PostgreSQL]
D --> D1[Samba/NFS]
E --> E1[Dev Tools]

```
So basically when `Proxmox Host` fails, do not trigger notifications on reliant monitors.
Fine would be also , to display the depencies in a tree or something like this.

Look for monitor configuration and notification logic in the codebase, likely in models or services. Understand how monitors are currently evaluated and how alerts are triggered. The feature requires adding dependency relationships between monitors and modifying alerting logic to suppress notifications when a parent monitor is down. Check existing UI components for displaying monitor lists to add a dependency tree view.

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