Deprecate the /self API endpoint across all routes

[vikasosmium]

Issue Description

Deprecate the /self API endpoint across all routes from the website-backend. And introduce a new route that will serve the purpose of /self.

Below is the mentioned list of routes where /self is currently being used:

1. • GET /arts/user/self
2. • GET /extensionRequests/self
3. • GET /stocks/user/self
4. • GET /tasks/self
5. • PATCH /tasks/self/:id
6. • PATCH /tasks/assign/self
7. • POST /trading/stock/new/self
8. • PATCH /users/self
9. • GET /users/self
10. • PUT /users/self/intro
11. • GET /userStatus/self
12. • PATCH /userStatus/self

Expected Behavior

The API Endpoint should have a more meaningful name.

Current Behavior

Reproducibility

• This issue is reproducible
• This issue is not reproducible

Severity/Priority

• Critical
• High
• Medium
• Low

Additional Information

Checklist

• I have read and followed the project's code of conduct.
• I have searched for similar issues before creating this one.
• I have provided all the necessary information to understand and reproduce the issue.
• I am willing to contribute to the resolution of this issue.

[vikasosmium]

Can you please assign this issue to me?
@vinit717