GPT-OSS think mode

[ChengYen-Tang]

The GPT-OSS model supports setting the thinking level. Ollama has placed this setting in the original Think parameter, making it support bool or string.
https://github.com/ollama/ollama/blob/df335aac/api/types.go#L87-L92

How to set the thinking level in OllamaSharp

[awaescher]

@byronmcclain submitted a clever pull request to handle this which is merged in version 5.4.5.
Would you check if you can close this issue?