Support for storage information in redfish plugin

Feature Request

The current redfish plugins only supports thermal and power informations from the redfish standard.

Proposal:

Adding support for the redfish's storage metrics

Current behavior:

Only metrics for power, fans and thermals are gathered by telegraf

Desired behavior:

Add storage metrics to existing thermals, fans and power. Maybe the possibility to enable or disable each of theses categories to fit any use case.

Use case:

I would like this feature be able to monitor physical servers through their management interface (iLO for HPE or iDRAC for Dell, maybe others) to trigger alarms through my monitoring stack.
I know that i could use SNMP, but it's more work to implement, needing to specify the whole snmp structure that i want, and i'd rather not enable IPMI (which we don't really use) to avoid adding another open service.
Redfish being implemented as part of the existing web service of these management interfaces, it also doesn't require much configuration on the server side.