Show how many "likes" a mentor has

We can show how many people added a mentor to their favorite list.
It's not like a real like but it's a nice indication that might encourage mentor to share their profile even more.

Technical:
**Server**
- We will add another property for a mentor (user) - likes count.
- Every time someone toggles the mentor from their favorite list, the server (1) will add the mentor to the user's favorite list [like it does today] (2) will increase / decrease the counter
- The counter will be part of the mentor response

**Client**

Something like