Reorganize the Khepri tree

[dumbbell]

Note

The description is to be written.

Goal:

<root>
|-- users
|   `-- $username
|-- vhosts
|   `-- $vhost
|       |-- user_permissions
|       |   `-- $username
|       |-- exchanges
|       |   `-- $exchange
|       |       |-- bindings
|       |       |   |-- queues
|       |       |   |   `-- $queue
|       |       |   `-- exchanges
|       |       |       `-- $exchange
|       |       |-- serial
|       |       `-- user_permissions
|       |           `-- $username
|       |-- queues
|       |   `-- $queue
|       `-- runtime_params
|           `-- $param_name
|-- runtime_params
|   `-- $param_name
|-- mirrored_supervisors
|   `-- $group
|       `-- $id
`-- node_maintenance
    `-- $node