Save push notified messages to the database without entering the app

[rapterjet2004]

🚧 TODO

• Fix 412 error on pulling chatMessages

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not needed
• 🔖 Capability is checked or not needed
• 🔙 Backport requests are created or not needed: /backport to stable-xx.x
• 📅 Milestone is set
• 🌸 PR title is meaningful (if it should be in the changelog: is it meaningful to users?)

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/4463-talk.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud Talk app.

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	94	152
Errors	132	88

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	16	16
Dodgy code	74	74
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	5	5
Security	1	1
Total	108	108

Lint increased!

[mahibi]

@rapterjet2004 Sorry, i haven't seen in time you picked this issue. 🙈
I fear working here now might cause problems as i plan to continue with #4422 in the next days. There would be complicated merge conflicts.
Could you pause this and work on other parts not related to the offline feature?