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/jest.config.js

@@ -11,8 +11,8 @@ module.exports = {
   coverageThreshold: {
     global: {
       branches: 9,
-      functions: 9,
-      lines: 16,
+      functions: 10,
+      lines: 17,
       statements: 16
     }
   }