feat(JSON Validator): Add JSON validation class

[shawnkchan]

Summary

Raising this draft PR to request feedback on some functions I wrote to handle JSON validation according to the VDA5050 schemas. This PR includes:

1. JSON validator and relevant utility functions.
2. Generator class to create VDA5050 JSON objects with random values for unit testing.
3. Basic unit test to test the JSON validator

I'll add the remaining test cases for the other VDA5050 schemas after this design is approved.