[Bicep Visualizer] Different nested resources with same symbol name are shown as one

**Bicep version**
v0.3.539

**Describe the bug**
We have 2 secrets (each secret for one key vault), but on diagram only one is shown:

**To Reproduce**:
```
@secure()
param secretValue string
@secure()
param secretValue2 string

resource keyVault 'Microsoft.KeyVault/vaults@2021-04-01-preview' = {
name: 'kv-${uniqueString(resourceGroup().id)}'
location: location
properties: {
enableRbacAuthorization: true
sku: {
name: 'standard'
family: 'A'
}
tenantId: subscription().tenantId
}
resource secret 'secrets' = {
name: 'mySuperSecret'
properties: {
value: secretValue
}
}
}

resource keyVault2 'Microsoft.KeyVault/vaults@2021-04-01-preview' existing = {
name: 'kv-${uniqueString(resourceGroup().id)}-sys'
resource secret 'secrets' = {
name: 'mySuperSecret'
properties: {
value: secretValue2
}
}
}
```

**Additional context**
Additionally, arrows should point in the other direction - from parent resource to the child to indicate the deployment flow (first parent, then child).