adding re-ranking

[vaiju1981]

1. Ability to call rerank method - done
2. Sorting the results based on the score - done
3. Adding test suites - Done

[vaiju1981]

@kherud this is ready for review.

[kherud]

Hey @vaiju1981 thank you again for another awesome PR! It looks great, I made a few small changes and other additions from issues/requests that came up the last days, I hope that's ok:

• The biggest change was probably to remove jackson, and simply use a string builder instead. Jackson is quite a heavy dependency and we should try to keep dependencies as simple as possible.
• I updated to the newest llama.cpp version.

If everything goes well now, I'll merge it and release a new version.

[vaiju1981]

@kherud sounds great. Your changes look good.

[kherud]

Version 4.1.0 is published 🎉