Add integration test for assesement result schema validation

[ShanshanHe]

Description

Add integration test for assesment result schema validation

Solution idea(s)

Run json schema validation on assessment result including package-analysis-result.json and api-analysis-result.json.

[ShanshanHe]

PR here: https://github.com/aws/porting-assistant-dotnet-client/pull/441

[jonlouie]

Closing- completed by #441