Add User Avatars for Collaborators

[Slacky300]

Description: Enhance the collaborator presence feature by adding user avatars next to the names of collaborators who are currently editing a document. This will make it easier to identify who is working on the document in real-time.

Tasks:

• Allow users to upload a profile picture during account creation or in the settings.
• Display these avatars next to collaborator names in the document editing interface.
• Implement default avatars for users who do not upload a profile picture.
• Ensure that the avatars are displayed consistently across different parts of the application.

Expected Outcome: A more personalized collaboration experience where users can easily recognize their collaborators by their avatars.