support markdown and make links clickable for scheduled messages

[sowjanyakch]

Resolve #5826

• support markdown in scheduled messages.
• Make links clickable in scheduled messages.
• Add menu item "Go To Thread" when the message is a thread and also add parent message when the message is a reply to another message in thread.
• Fix a bug with edit text(cursor always at the end and adds text at the end irrespective of chosen cursor position).

🚧 TODO

• ...

🏁 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]

Codacy

Lint

Type	master	PR
Warnings	98	98
Errors	0	0

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	10	10
Dodgy code	54	54
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	4	4
Security	1	1
Total	81	81

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/5830.apk



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

[mahibi]

/backport to stable-23.0