feat: support setting maxConcurrentChunks for Generic OpenAI embedder

[hdelossantos]

Pull Request Type

• [ x] ✨ feat
• [ ] 🐛 fix
• [ ] ♻️ refactor
• [ ] 💄 style
• [ ] 🔨 chore
• [ ] 📝 docs

Relevant Issues

resolves #2654

What is in this change?

Adds an advanced settings collapsible menu to the Generic OpenAI embedder configuration with input to optionally set max concurrent chunks. If no input is provided, the maxConcurrentChunks variable is defaulted to 500.

Additional Information

Developer Validations

• [x ] I ran yarn lint from the root of the repo & committed changes
• [x ] Relevant documentation has been updated
• [x ] I have tested my code functionality
• [x ] Docker build succeeds locally

[timothycarambat]

Excellent work, just made a minor update to make the maxEmbeddingChunks a class getter so make sure the value in the ENV is parsed to number and always something we can work with.

Also updated field UI to the new UI so it looks right.