Adds an info and list command for getting more details on subscriptions

[somtochiama]

somma@odysseus:~/workspace/superfly/corrosion$ target/debug/corrosion -c _personal/config.toml subs info --hash 6525eb339b115733
{
  "hash": "6525eb339b115733",
  "id": "fe4523c2-c1ef-4d49-99e7-cd35ac8632de",
  "last_change_id": 0,
  "original_query": "SELECT id,title,completed_at FROM todos",
  "path": "./test-corrosion/subscriptions/fe4523c2c1ef4d4999e7cd35ac8632de",
  "statements": [
    {
      "todos": "SELECT todos.id AS __corro_pk_todos_id, id AS col_0, title AS col_1, completed_at AS col_2 FROM todos WHERE (todos.id) IN __corro_sub.temp_todos"
    }
  ]
}

[jeromegn]

Looks good except for the naming inconsistency.