redfish rest_request() to use args_to_objects()
redfish rest_request() to use args_to_objects()

- Callers may include inline python code strings to define arguments.
  This predominantly benefits robot callers.

  For example, instead of calling like this:
    ${data}=  Create Dictionary  HostName=${hostname}
    Redfish.patch  ${REDFISH_NW_PROTOCOL_URI}  body=&{data}

  Callers may do this:

    Redfish.patch  ${REDFISH_NW_PROTOCOL_URI}
    ...  body=[('HostName', '${hostname}')]

Change-Id: I3b251582d6f7e77959a50b9696f338eb11fe2506
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation