Contacts activity

[sowjanyakch]

partly resolves #3794

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This PR implements ContactsActivity in Jetpack Compose using coroutines.

• Display user avatar and name for contacts.
• Add sticky headers for contacts.
• Create 1-1 room on clicking a contact.
• Implement search for contacts.

Image caching for user avatars and theming will be implemented in a different PR.

🖼️ Screenshots

Contacts	Search	Create room for contacts

🚧 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?)

[rapterjet2004]

Great Job! 👍🏾 It works on my emulator

Just need to implement

• Create new public conversation
• Proper theming

Me and @mahibi are also doing a lot of work on #3952 to get offline conversations + chatting working. I don't think there is much overlap with your PR, but just a heads up in case there are merge conflicts.

[mahibi]

Great to have a kickoff with jetpack compose 🚀
From my side this can be merged once the remarks from Julius are solved and issues/features should be fixed/done in followup PRs.

[mahibi]

One thing i realized when testing are some bugs that existed already before this PR:

1. I have 2 accounts on sermo and with my account "Marcel" i am not able to see the account "marcel2" in the contacts. Maybe i get something wrong but i don't have an idea which could explain why it shouldn't be shown. When i search for it, it appears, but it's not in the list by default.

2. When opening a conversation and go to Conversation info to add participants, the search is broken. When i enter a name, it won't appear in the results list. Then i delete the search and try and, and then more results appear than before.
   Bug report is search in contact controller buggy on first search #2037

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/3936-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.

[mahibi]

@sowjanyakch
Can you rebase on master? Or as the rebase was not done regulary and may be difficult now, you can also merge master into this branch. For future branches please always use rebase and do it regulary.

please also fix warnings from https://app.codacy.com/gh/nextcloud/talk-android/pull-requests/3936/issues