[RFE] Introspection rule actions value formatting for complex values

Introspection rule actions cannot use formatting for non-string values. Sometimes we need to set a complex non-string value on a node via inspection rules. We may also want this non-string value to contain a reference to the introspection data.

Steps to reproduce

Here we use the example of setting a root device hint for the serial of the disk determined by inspection to be the root device. The properties.root_device attribute should be a dict mapping hint names (e.g. "serial") to hint values (e.g. a disk serial number).

$ cat > rule << EOF
{
    "actions": [
        {
            "action": "set-attribute",
            "path": "properties/root_device",
            "value": {
                "serial": "{data[root_device][serial]}"
            }
        }
    ],
    "conditions": [
        {
            "field": "node://properties.root_device",
            "op": "is-empty"
        }
    ]
}
$ openstack baremetal introspection rule import rule
+--------------------------------------+-------------+
| UUID | Description |
+--------------------------------------+-------------+
| 8e20fa94-cf46-4fcb-93f4-2dfeda4752dd | None |
+--------------------------------------+-------------+
$ openstack baremetal introspection rule show 8e20fa94-cf46-4fcb-93f4-2dfeda4752dd
+-------------+----------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------+----------------------------------------------------------------------------------------------------------------------------+
| actions | [{u'action': u'set-attribute', u'path': u'properties/root_device', u'value': {u'serial': u'{data[root_device][serial]}'}}] |
| conditions | [{u'field': u'node://properties.root_device', u'op': u'is-empty'}] |
| description | None |
| uuid | 8e20fa94-cf46-4fcb-93f4-2dfeda4752dd |
+-------------+----------------------------------------------------------------------------------------------------------------------------+

Now start introspection on a node, for example:

$ ironic node-set-provision-state <node> inspect

Expected result:

The ironic node gets updated with properties/root_device={"serial": "<serial number>"}

Actual result:

The ironic node gets updated with properties/root_device={"serial": "{data[root_device][serial]}"}

Proposed solution:

For any action parameters marked as FORMATTED_PARAMS, inspector currently formats them if they are of type string. Inspector should also recursively check all non-string objects (dicts, lists) and format all strings contained nested within them.