new field in node's BALLOT: IPROTO_BALLOT_INSTANCE_NAME

[TarantoolBot]

Product: Tarantool
Since: 3.0
Root document:

• https://www.tarantool.io/en/doc/latest/dev_guide/internals/iproto/replication/
• https://www.tarantool.io/en/doc/latest/reference/internals/iproto/keys/#iproto-ballot-keys
  SME: @ sergepetrenko

Details

The node's ballot (IPROTO_BALLOT) receives a new field:
the name of the node (the same as in box.cfg.instance_name or
box.info.name):
Key: IPROTO_BALLOT_INSTANCE_NAME = 0x0a
Value: MP_STR, representing the instance name.
Requested by @sergepetrenko in tarantool/tarantool@70f66fa

Related to #3504