feat: automatically discover inventory (#127)

## Fully automated inventory gathering now works!

Boot up harmony_inventory_agent with `cargo run -p harmony_inventory_agent`
Launch the DiscoverInventoryAgentScore , currently available this way :

`RUST_LOG=info cargo run -p example-cli -- -f Discover -y`

And you will have automatically all hosts saved to the database. Run `cargo sqlx setup` if you have not done it yet.

Co-authored-by: Ian Letourneau <ian@noma.to>
Reviewed-on: #127
Co-authored-by: Jean-Gabriel Gill-Couture <jg@nationtech.io>
Co-committed-by: Jean-Gabriel Gill-Couture <jg@nationtech.io>

examples/nanodc/src/main.rs

@@ -87,8 +87,7 @@ async fn main() {
     let inventory = Inventory {
         location: Location::new("I am mobile".to_string(), "earth".to_string()),
         switch: SwitchGroup::from([]),
-        firewall: FirewallGroup::from([PhysicalHost::empty(HostCategory::Firewall)
-            .management(Arc::new(OPNSenseManagementInterface::new()))]),
+        firewall_mgmt: Box::new(OPNSenseManagementInterface::new()),
         storage_host: vec![],
         worker_host: vec![
             PhysicalHost::empty(HostCategory::Server)