Add test to enforce property OEM URI patterns

[mraineri]

When in the context of an OEM object, check that the references to OEM resources follow the "OEM URIs" clause in the spec.

To avoid URI collisions with other OEM resources and future Redfish standard resources, the URIs for OEM resources within the Redfish resource tree shall be in the form:

<BaseUri>/Oem/<OemIdentifier>/<ResourcePath>

where

<BaseUri> is the URI segment of the standard Redfish resource starting with /redfish/ where the Oem property is used. For example, /redfish/v1/Systems/3AZ38944T523.
<OemIdentifier> is the unique identifier of the OEM, including possible subdivisioning, that follows the same naming as defined in the OEM-specified object naming clause. Separator underscores (_) may be excluded for improved readability.
<ResourcePath> is the path to the OEM-defined resource. This path might contain multiple segments for cases where OEM-defined resources are subordinate to an OEM-defined resource. Each segment in the path contains the name of an OEM-defined resource.