Optimized profile page by changing endpoints and respective payload, killed bug

Changed/created endpoints for profile page:
- to fetch just a total posts count instead of all posts (twice), one to get the total number and the other to get a list
- created a new endpoint just to get username and user id instead of the users endpoint which fetches too much unnecessary data,
- debugged streak undefined bug (happens when user has no posts) using v-if="streak == undefined" to show empty string, and v-else to show badges when user has written at least on epost.