[1.x] TDB (iproto): working with failover coordinator

[xuniq]

Product: Tarantool DB
Since: 1.2.4
Root documents:

• https://www.tarantool.io/en/tarantooldb/doc/1.x/install_and_upgrade/install/#install-requirements
• https://www.tarantool.io/en/tarantooldb/doc/1.x/reference/roles/#failover-coordinator

SME: @ a1div0

Details

See sub issues for details: