`tt replicaset roles add` adds roles in the tarantool replicaset

[TarantoolBot]

Product: tt cli
Since: tt 2.5.0
Audience/target: all
Root document: https://www.tarantool.io/en/doc/latest/reference/tooling/tt_cli/replicaset/
SME: @ themilchenko @ oleg-jukovec

Details

tt replicaset roles add adds roles in the tarantool replicaset
with cluster config (3.0) or cartridge orchestrator.

This patch introduces new command for the replicaset module.

add [--cartridge|--config|--custom] [-f] [--timeout secs]
    <APP_NAME:INSTANCE_NAME> <ROLE_NAME> [flags]

It is possible to provide cartridge, config or custom flag to
explicitly state which orchestrator to use. ROLE_NAME is a role to add
into local cluster config in case of cluster config orchestrator and
directly into all instances of replicaset in case of cartridge
orchestrator. Command supports cartridge and cluster config
orchestrators only for the entire application.

There are flags supported by this command:

• --global (-G) for a global scope to add a role (only for cluster config
  orchestrator);
• --instance (-i) string for an application name target to specify
  an instance to add a role;
• --replicaset (-r) string for an application name target to specify
  a replicaset to add a role;
• --group (-g) string for an application name target to specify a group
  (vshard-group in the Cartridge case) to specify a group to add a role;
• --force (-f) skips instances not found locally in cluster config orchestrator.

Closes #914
Requested by @themilchenko in tarantool/tt@690aa45.