Add the feature to have custom config

[Anindyadeep]

🚀 The feature

Add support for validating and accepting custom config class schema

Motivation, pitch

Currently, there is very less support for custom config classes, however, we can not fully generalised that all provider or object will have same configurations. There could be additonal configs or may be same configs but names might be changes.

One way to solve this is to inherit from the BaseConfigClass and then make a custom config class. However, the schema validation code does not supports validating custom config.