fix(push-notification): Notification not dispatching click when received in foreground

[AndrewKravchenko]

Based on #1478

Added generateUniqueId method to prevent overwriting the last notification

[tafelnl]

I think you've got more chance of getting this merged, if you only make this about the uniqueId part. PRs should be as small as possible, and with the smallest scope possible. The other PR you mentioned will then be solely about the click-dispatch thing