Fix multiple profile creation for one user

[ceydanursen]

🧱 Description

The same user can have only one profile. We should change the functionality of the profile endpoint so that this condition is met.

📋 Acceptance Criteria

• [x] The same user is able to create only one profile.

[ozankrkya]

We have fixed this issue and merged to the develop-backend. Thus, i am closing this issue.