fix manager reset action when no allowed values for reset type are provided

[vsvastey]

Sometimes Manager.Reset action doesn't provide AllowableValues for ResetTypes, like that:

  "Actions": {
    "#Manager.Reset": {
      "target": "/redfish/v1/Managers/1/Actions/Manager.Reset/"
    }
  }

In this case current implementation provides a payload {"Action": "Manager.Reset"} which doesn't work at least for HP gen9 (iLO4) that I can test on. I get Base.0.10.ActionNotSupported error.

According to the specification:

    Manager_v1_18_0_ResetRequestBody:
        ....
        ResetType:
          ...
          x-longDescription: This parameter shall contain the type of reset.  The
            service can accept a request without the parameter and perform an implementation
            specific default reset.  Services should include the @Redfish.AllowableValues
            annotation for this parameter to ensure compatibility with clients, even
            when ActionInfo has been implemented.
         ...

it seems like an empty payload should be sent in this case.

I've tested an empty payload on HP gen9 and it works as expected.

Please, consider the fix for this case.

[stmcginnis]

Looks reasonable to me. @leslie-qiwa originally added this special handling for HPE awhile back. Let's just wait a bit to see if they want to chime in here or confirm from their environment.

[leslie-qiwa]

I can not find such a server in our system now. The change looks good for me. You can go ahead merging, and I'll let you know if the issue comes up.