Added Warranty class and Asset properties

[PeteHart]

Add Warranty class and colour property to Asset

Summary

This PR is part of the broader effort to support lighting assets in RealEstateCore, with most of the foundational work happening in Brick Schema. On the REC side, this adds:

• New Warranty class (dtmi:org:w3id:rec:Warranty;1) — extends Event to represent warranty information for assets
• New warranty relationship on Asset — links assets to their warranty records
• New colour property on Asset — string property to capture asset colour

Changes

File	Change
Source/DTDLv2/RealEstateCore/Asset/Asset.json	Added colour property and warranty relationship
Source/DTDLv2/RealEstateCore/Event/Warranty.json	New interface extending Event

Context

These additions complement the lighting equipment classes already defined via Brick Schema (Lighting_Equipment, Luminaire, Luminaire_Driver, etc.) by providing asset-level metadata (colour, warranty) that is relevant across all asset types, including lighting.

[cbupp]

Looks good to me