Update WebSocket data handling for files and system messages

[anakin78z]

See #6081

When receiving a WebSocket chat comment with a file attachment, fetch messages via REST call to get user specific file paths.
This allows the user to display media without needing to wait on the insurance call to trigger.

Also checks for system messages that need to be localized for the user. This follows the logic of the web app. However, since it doesn't look like we do localization in the Android app, it's set to fetch new data for any system message that is not on the list of untranslated system messages. Partially implements #6064

🏁 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://github.com/nextcloud/talk-android/actions/runs/24935776966/artifacts/6641289039
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)

[github-actions]

APK file: https://github.com/nextcloud/talk-android/actions/runs/24961225772/artifacts/6648778858
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	88	88
Errors	0	0

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	10	10
Dodgy code	53	53
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	4	4
Security	1	1
Total	80	80

[mahibi]

will have a look soon!