Replace the avatar to first letter when the user provided her name

[moranw]

We got some feedback that the new avatars may feel non personal/ not real people.
If the name for the testimony giver contains the string "אנונימי" or "בדוי" then it should show the avatar on the circle.
Otherwise it should be the first letter like it used to be.

No UI is provided here, I want to see a screenshot before you push to see if it makes sense or we should just leave it as is.