Add IBM watsonx provider

[PedroGomes02]

Summary

Add IBM watsonx provider to providers.

Resolves #11084

I have to change "pandas" library dependency because Poetry version solving failed:

Checklist

• [ ] This change requires a documentation update, included: Dify Document
• [x] I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• [x] I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• [x] I've updated the documentation accordingly.
• [x] I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods

[crazywoola]

Please fix the lint.

[PedroGomes02]

Lint fixed ✅

[crazywoola]

Hello I sent a dm message to you in discord.

FYI, here is the message in case you missed it.

We plan to test v1.0 around Dec 5 in our staging environment. Currently, we do not accept tools and model providers anymore until the v1.0 is released.

However, if you are interested in testing it out, and make tools & llms to that version.

Please fill this form https://forms.gle/8sQWmqPWCo5GEn8w7. We only collect emails for accessing our staging environment by this whitelist. You can use this email to login into our system then. No spam 📧

Here is the discord channel https://discord.gg/H6zB7zAW I will list the docs and other necessary information in 👆 channel until I get updates from our dev team.

Thanks again for your unwavering support.❤️