feat: add subscription manager to handle subscription sharing (#1517)

* feat: add subscription manager to handle subscription sharing

* fix(services): add missing methods to the interface

* fix(services): add subscription manager specs

* feat(snjs): add subscriptions e2e tests

* fix(snjs): add wait in subscription cancelling test

* fix(snjs): checking for canceled invitations in tests

* fix(snjs): add e2e test for restored limit of subscription invitations

* chore(lint): fix linter issues

packages/services/src/Domain/Subscription/SubscriptionClientInterface.ts

@@ -0,0 +1,8 @@
+import { Uuid } from '@standardnotes/common'
+import { Invitation } from '@standardnotes/models'
+
+export interface SubscriptionClientInterface {
+  listSubscriptionInvitations(): Promise<Invitation[]>
+  inviteToSubscription(inviteeEmail: string): Promise<boolean>
+  cancelInvitation(inviteUuid: Uuid): Promise<boolean>
+}