feat: Openrouter reasoning support

[SpeedCrash100]

Description

Added initial support of thinking retrieval from Openrouter.

Currently. It is required to set up extraBodyProperties and provider correctly:

Deepseek is working, but some models may not return reasoning even if they are thinking. Can be verified with curl.

# Note: openai here, idk why, but with `openrouter` it will not work
  - provider: openai
    apiBase: https://openrouter.ai/api/v1
    apiKey: sk-*
    name: Openrouter Deepseek R1 FREE
    model: deepseek/deepseek-r1:free
    requestOptions:
      extraBodyProperties:
        stream: true
        include_reasoning: true

Checklist

• [] The relevant docs, if any, have been updated or created
• [] The relevant tests, if any, have been updated or created

Screenshots

Testing instructions

1. set up config.yaml to use openrouter DeepSeek R1 model and add extraBodyProperties: from Description section.
2. Send chat request and ensure the Thinking... section appeared
3. It should be tested that Ollama Deepseek R1 still working.

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[SpeedCrash100]

Will wait for #4559 might be handled here already