[PM-18578] Don't enable automatic tax for non-taxable non-US businesses during invoice.upcoming (#5443)

* Only enable automatic tax for US subscriptions or EU subscriptions that are taxable.

* Run dotnet format

src/Core/Billing/Extensions/CustomerExtensions.cs

@@ -5,6 +5,15 @@ namespace Bit.Core.Billing.Extensions;
 
 public static class CustomerExtensions
 {
+    public static bool HasBillingLocation(this Customer customer)
+        => customer is
+        {
+            Address:
+            {
+                Country: not null and not "",
+                PostalCode: not null and not ""
+            }
+        };
 
     /// <summary>
     /// Determines if a Stripe customer supports automatic tax