Profile Pictures: Followup

[FelberMartin]

After the basic functionality of profile pictures is merged (#111) take care of the following:

• Fix bug described below -> Not directly related to profile pictures -> extracted to Post items get recomposed when new post is added #203
• Click on profile picture shows popup dialog
  • This should only be possible on posts and conversation header imo
  • The "send message" button has been postponed, see Profile picture dialog: send message button #213
• Show profile picture in ...
  • Conversation overview
  • Conversation header for DMs
  • User search (channel creation)
  • Conversation members
  • User settings screen
• Show in notifications -> this is not straight forward and seen as lower priority, see I extracted it into Notification improvements #216

This is the follow-up issue for #63.

[ahbitaqu]

Maybe we can also address this minor issue in this follow-up:
The profile pictures reload Everytime a message is sent, and while the message is sending they disappear completely
https://github.com/user-attachments/assets/91928886-4505-4afa-9a0e-4d0243fbcbd9

[julian-wls]

#178 introduced icons in the Account information section of the settings screen. Instead of displaying the person icon next to the full name we could add a profile picture here as well.