FEAT: Improve Profile viewing of existing users

[muntaxir4]

Is your feature request related to a problem? Please describe.
Currently, the Profile View has a few usability issues:

• The data tabs (e.g., user posts, activity) appear empty, leading to a poor user experience.
• The "Follow" button does not update its state immediately after clicking; the page needs to be refreshed for the changes to take effect.
• If a user does not have a profile picture, no default image is displayed.

Describe the solution you'd like

• Ensure that the data tabs display relevant content dynamically instead of appearing empty.
• Implement a state update mechanism so that the "Follow" button reflects changes immediately without requiring a page refresh.
• Display a default profile picture (e.g., a placeholder avatar) for users who have not uploaded an image.

Would you like to work on the issue?

• Yes
• No
• Other: