Update cohere model integrations

[Anirudh31415926535]

Why are these changes needed?

This PR aims to fix the cohere integration to the ag2 repo. This PR essentially contains the changes here and here

Checks

• I've included any doc changes needed for https://docs.ag2.ai/. See https://docs.ag2.ai/docs/contributor-guide/documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[marklysze]

Hey @Anirudh31415926535, while looking into adding structured output support I saw that the V2 API seemed easier to work with, more aligned with other APIs. I've started work on it in #369. Do you think V2 is better to move forward with?

[Anirudh31415926535]

Hey @Anirudh31415926535, while looking into adding structured output support I saw that the V2 API seemed easier to work with, more aligned with other APIs. I've started work on it in #369. Do you think V2 is better to move forward with?

Hey @marklysze Yes absolutely! Migrating to the cohere integration to V2 was something that we were thinking about as well haha! Would def appreciate the help here! I can help to review the PR if you're willing to contribute!
But I am not sure where the V2 api integration comes into the PR you'd linked though #369 Is it still in progress? Or am I missing something there haha...

[marklysze]

Hey @Anirudh31415926535, while looking into adding structured output support I saw that the V2 API seemed easier to work with, more aligned with other APIs. I've started work on it in #369. Do you think V2 is better to move forward with?

Hey @marklysze Yes absolutely! Migrating to the cohere integration to V2 was something that we were thinking about as well haha! Would def appreciate the help here! I can help to review the PR if you're willing to contribute! But I am not sure where the V2 api integration comes into the PR you'd linked though #369 Is it still in progress? Or am I missing something there haha...

:), my bad, wrong PR! it's #370, sorry!

Yes, if we can work on that one that would be better, V2 is so much easier to work with!

Please have a look at the PR and if you're happy to continue there feel free to close this one.