Remove non-standard members from Thing Descriptions

[benfrancis]

The Zigbee adapter currently adds a lot of non-W3C standard metadata to Thing Descriptions about Zigbee devices, particularly about their properties, e.g.:

• name
• value
• profileId
• endpoint
• clusterId
• attr
• attrId
• fireAndForget
• bindNeeded
• configReportNeeded
• initialReadNeeded

These metadata do not need exposing at the WoT layer and should be removed.