[Feature]: Add VNET connectivity status output for Get-AzVirtualHubVnetConnection

### Description of the new feature

Sample output from `Get-AzVirtualHubVnetConnection`

```
Name :
Id : /subscriptions//resourceGroups//providers/Microsoft.Network/virtualHubs//hubVirtualNetworkConnections//RemoteVirtualNetwork : /subscriptions//resourceGroups//providers/Microsoft.Network/virtualNetworks/
EnableInternetSecurity : False
ProvisioningState : Succeeded
RoutingConfiguration : {
"AssociatedRouteTable": {
"Id": "/subscriptions//resourceGroups//providers/Microsoft.Network/virtualHubs//hubRouteTables/
},
"PropagatedRouteTables": {
"Labels": [
"",
"",
"",
""
],
"Ids": [
{
"Id": "/subscriptions//resourceGroups//providers/Microsoft.Network/virtualHubs//hubRouteTables/"
}
]
},
"VnetRoutes": {
"StaticRoutes": []
}
}
```

Currently this do _not_ include the _connectivity status_ of the VNET connection, including this would be a big improvement as it would open up possibilities for more automation to such as handling VNETs that are in a disconnected state.


Please add :pray:

### Proposed implementation details (optional)

_No response_

Start by locating the Get-AzVirtualHubVnetConnection cmdlet implementation and the model or API response that supplies its output. Trace how the existing VNET connection properties are exposed, then verify that connectivity status appears in the command output and that the relevant tests cover it.

Written by the indexing model from the issue text.