Support for MongoDB clusters / vCore (#22512)

* Initial support for MongoDB clusters / vCore

* Get cluster connection string from arm

* Preserve Azure account for any auth type

When a service has been selected through the Azure
browser, we want to preserve the Azure account
information even if a different authentication has
been selected. This allows doing ARM operations
using the signed in Azure account for any resources
including those with a different login types such
as clusters.

extensions/azurecore/src/azureResource/interfaces.ts

@@ -50,6 +50,7 @@ export interface DbServerGraphData extends GraphData {
 	properties: {
 		fullyQualifiedDomainName: string;
 		administratorLogin: string;
+		connectionString: string;
 	};
 }