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/snjs/lib/Services/ComponentManager/ComponentViewer.ts

@@ -2,10 +2,8 @@ import { SNPreferencesService } from '../Preferences/PreferencesService'
 import {
   ComponentViewerInterface,
   ComponentViewerError,
-  Environment,
   FeatureStatus,
   FeaturesEvent,
-  Platform,
   AlertService,
 } from '@standardnotes/services'
 import { SNFeaturesService } from '@Lib/Services'
@@ -34,6 +32,8 @@ import {
   PayloadTimestampDefaults,
   IncomingComponentItemPayload,
   MessageData,
+  Environment,
+  Platform,
 } from '@standardnotes/models'
 import find from 'lodash/find'
 import uniq from 'lodash/uniq'