add compile option compose-node-name

[gburiola]

Fixes #932

INVENTORY USED FOR TESTING

$ tree inventory/targets
inventory/targets
├── prod
│   ├── finance.yaml
│   └── hr.yaml
└── test
    ├── finance.yaml
    └── hr.yaml

COMPILED WITHOUT NEW FLAG

$ ./kap.sh compile
Rendered inventory (0.07s)
Compiled test.finance (0.00s)
Compiled prod.finance (0.00s)
Compiled test.hr (0.00s)
Compiled prod.hr (0.00s)

$ tree compiled
compiled
├── prod.finance
│   └── README.md
├── prod.hr
│   └── README.md
├── test.finance
│   └── README.md
└── test.hr
    └── README.md

COMPILED WITH NEW FLAG

$ ./kap.sh compile --compose-node-name
Rendered inventory (0.07s)
Compiled test.hr (0.00s)
Compiled prod.finance (0.00s)
Compiled prod.hr (0.00s)
Compiled test.finance (0.00s)


$ tree compiled
compiled
├── prod
│   ├── finance
│   │   └── README.md
│   └── hr
│       └── README.md
└── test
    ├── finance
    │   └── README.md
    └── hr
        └── README.md

[uberspot]

LGTM, although we should also updated docs/README here about this new capability.