User should have an option to Change display name

[Shanmugapriya03]

Currently, only when the user is being registered he can set the display name instead he should be given an option to change whenever he wanted

[Nephyx]

Hi, I have started working on this.

[Haider8]

Hi @Nephyx, what's the progress on this issue?

[Nephyx]

Hi, my apologies for the delay, had busy past couple of days.
I'm still working on this and will do my best to get it done asap.

I'd like this to work in a way where user will be able to change their display name with a command like /display-name {NEW_DISPLAY_NAME}. I'm currently in the process of modifying Python client for this and will also add a new API endpoint for handling display name changes in the database.