tt cartridge does not work with some cartridge-cli scenarios

[psergee]

It must be possible to replace cartridge-cli with tt cartridge command for existing cartridge applications. Currently some commands fails:

$ tt status
   • myapp:router: RUNNING. PID: 44692.
   • myapp:s1-master: RUNNING. PID: 44687.
   • myapp:s1-replica: RUNNING. PID: 44688.
   • myapp:s2-master: RUNNING. PID: 44689.
   • myapp:s2-replica: RUNNING. PID: 44690.
   • myapp:stateboard: RUNNING. PID: 44691.
   
$ tt cartridge replicasets setup --bootstrap-vshard
   • Set up replicasets described in /home/user/myapp/myapp/replicasets.yml
   ⨯ Failed to get replicasets configuration: Failed to use replicasets configuration file: stat /home/user/myapp/myapp/replicasets.yml: no such file or directory

$ tt cartridge replicasets list
   ⨯ Failed to get instances configuration: Failed to use instances configuration file: stat myapp/instances.yml: no such file or directory

$ tt cartridge failover status
   ⨯ Failed to connect to some instance: No running instances found

$ tt cartridge replicasets set-failover-priority router --replicaset router
   ⨯ Failed to get instances configuration: Failed to use instances configuration file: stat myapp/instances.yml: no such file or directory