Add support for network configuration

[mikemrm]

It would be nice if bmclib could change the network configuration settings such as switching between dhcp and static as well as defining the ip address information when setting to static.

[joelrebel]

@mikemrm theres some support for Network configuration changes, and it may just be that we need to expose the configuration parameter for Static/DHCP.

https://github.com/bmc-toolbox/bmclib/blob/master/cfgresources/cfgresources.go#L135

Feel free to take a stab at it, I'd be happy to help,
The newer ILO/IDRAC Redfish endpoints support PATCH for single configuration parameters - which would be ideal to start using, the current implementation updates all network related configuration in one POST request and needs the client has to ensure the BMC is reset for the changes to take effect,

https://github.com/bmc-toolbox/bmclib/blob/master/providers/hp/ilo/configure.go#L735
https://github.com/bmc-toolbox/bmclib/blob/master/providers/dell/idrac9/configure.go#L607
https://github.com/bmc-toolbox/bmclib/blob/master/providers/supermicro/supermicrox/configure.go#L187

bmcbutler is then able to work with some of the network configuration parameters,
https://github.com/bmc-toolbox/bmcbutler/blob/master/samples/cfg/configuration.yml#L72