[yamaps] Yandex.Maps

Follow-up to #2594385: Drupal 8 port

# Summary

Drupal 8 will have stable release very soon, so it's time to upgrade Yandex.Maps for 8.x
Let's concentrate all work in this task.
D8 all the things!
Start with D7 version and figure out how to port ;)

# Project URL

https://www.drupal.org/project/yamaps

# Where is the code?

on drupal.org

# Estimated completion date

A stable Drupal 8 release has been available since November 14, 2015.

# Dependencies

None for Drupal 8.

# Who's doing the port?

Andrew.Mikhailov, kala4ek

# What help do they need?

N/A

# D8 roadmap

#2607554: Port to Drupal 8. Block
#2607558: Port to Drupal 8. Widget
#2607560: Port to Drupal 8. Formatter
#2607562: Port to Drupal 8. Views

# Background and reference information

N/A