Renamed module names and made changes in init to reflect the change

[tinomaxthayil]

• Changed module names to _contexts, _context_recall, _faithfullness
• Changed faithfulness module name in answer_correctness.py
• Added the new names to init.py

[shahules786]

• file names for answer_correctness and other metrics also have to change
• Add unit tests? @jjmachan

[jjmachan]

yes check the documentation on how we are importing it and add tests that mimic that.
also not that critic is something that is now imported like ragas.metric.critic do think about if we should change it

[tinomaxthayil]

• Added test cases and made name changes for the rest of the modules.
• Critique name is not changed but test case is added for the expected import.

[jjmachan]

@tinomaxthayil and @shahules786 should we split this into 2 files?

[tinomaxthayil]

you meant Class and instance for _contexts?

[shahules786]

@jjmachan Not sure what is ideal here, since both are metrics to evaluate contexts, I would suggest to keep as it is.

[tinomaxthayil]

@jjmachan and @shahules786. There were _context_precision and _contexts with the same metrics from another push I assume. I split it into two files and made the init changes. The new files are _contexts and _context_relevancy

[shahules786]

This should now be _context_precision