language_models: Add thinking support to LM Studio provider (#32337)

It works similar to how deepseek works where the thinking is returned as
reasoning_content and we don't have to send the reasoning_content back
in the request.

This is a experiment feature which can be enabled from settings like
this:
<img width="1381" alt="Screenshot 2025-06-08 at 4 26 06 PM"
src="https://github.com/user-attachments/assets/d2f60f3c-0f93-45fc-bae2-4ded42981820"
/>

Here is how it looks to use(tested with
`deepseek/deepseek-r1-0528-qwen3-8b`

<img width="528" alt="Screenshot 2025-06-08 at 5 12 33 PM"
src="https://github.com/user-attachments/assets/f7716f52-5417-4f14-82b8-e853de054f63"
/>


Release Notes:

- Add thinking support to LM Studio provider
4ac7935589Umesh Yadav committed on 6/9/2025, 9:55:34 AM· committed by GitHubparentc75ad2f
2 files changedLine totals unavailable