Populate asset identity from OPC UA device information

[mfaferek93]

Populate the Component asset-identity fields from the connected OPC UA server's device information, so a connected device shows its nameplate in the entity tree without manual entry.

• Read ServerStatus/BuildInfo (ManufacturerName, ProductName, SoftwareVersion, BuildNumber) and, where exposed, the standard identification/nameplate nodes (Manufacturer, Model, SerialNumber, HardwareRevision, SoftwareRevision), and map them onto the asset-identity fields with per-field provenance.
• Feed the discovery merge so protocol-sourced identity ranks by source precedence.
• Acceptance: connecting an OPC UA server fills the identity fields without manual entry; an end-to-end test (server fixture -> identity -> x-medkit.identity with per-field provenance over the REST API) covers it without hardware.