USD Error Handling

We have added new Error schemas to help identify issues, for example the FnErrorAPI schema and FnWarningAPI schema.

These are used in the KatanaToUsd node for when conversion would be incomplete or in an error state.

The failing prims would have the FnErrorAPI schema or the FnWarningAPI schema applied to them which changes the primType of the failed prim and includes an error log in the USD code.

The schemas can be found in the UsdSchemaSet node and can be used to set a message on a prim:

An example can be found below with more info available in the developer guide.