Assessment: Add opus model support

[vprashrex]

Is your feature request related to a problem?
The current assessment model does not include the opus model, and there are issues with the enum handling in the response format. This can lead to confusion and inefficiencies when working with the assessment module.

Describe the solution you'd like

• Add opus model and its configuration in assessmentModel.ts file
• Enhance enum handling fix in the response format from the assessment module

Original issue

• Add opus model and its configuration in assesmentModel.ts file
• Enhance enum handle fix in response format from assessment module