Fix conversation search functionality and highlighting

[rapterjet2004]

• fixes Conversation search functionality does not work properly #4080

🚧 TODO

• Get it working again
• Fix highlighting
• Submit button destroys the searchViewDisposable. Need to figure out a way to fix that or disable it
  • I can perhaps monitor key presses and override the 'enter' key to do null
  • Alternatively, I could check for disposable every query and reinit if null

🏁 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?)

[rapterjet2004]

/backport to stable-20.0

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	86	86
Errors	131	131

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	11	11
Dodgy code	78	78
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	6	6
Security	1	1
Total	108	108

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/4088-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.