Show real user chains.

[grandmotivator]

We use contact.is_real, so that users mark whether they saw other users in reality.

If the first user marked the second user so, and the second user marked the third user so, then the first user, when he views the profile / contact of the third user, should see a chain like this `REAL #ID(second_user) -> #ID(third_user).

There can be many chains and each of any length. So we test the theory https://en.wikipedia.org/wiki/Six_degrees_of_separation

Chains must be displayed in the view of each contact on the site and in the telegram bot.

[amitleuva1987]

@grandmotivator , let me check this. If you have some more details, please post.