fix: allow resubscribing (#1901)

Currently users who cancel their plan are stuck without the ability to
resubscribe. This allows them to choose a plan to subscribe

This assumes that a Subscription in the "INACTIVE" state means that the
plan has been paid but canceled.

No tests have been done to determine the relation between "PAST_DUE" and
"INACTIVE" states within our context.

packages/lib/constants/app.ts

@@ -12,3 +12,5 @@ export const NEXT_PRIVATE_INTERNAL_WEBAPP_URL =
 export const IS_BILLING_ENABLED = () => env('NEXT_PUBLIC_FEATURE_BILLING_ENABLED') === 'true';
 
 export const API_V2_BETA_URL = '/api/v2-beta';
+
+export const SUPPORT_EMAIL = 'support@documenso.com';