Chore: Add initializer for `FunctionCall`

[thekoc]

What

Add a public initializer for ChatQuery.ChatCompletionMessageParam.ChatCompletionAssistantMessageParam.ChatCompletionMessageToolCallParam.FunctionCall, allowing it to be created programmatically.

Why

When converting chat history from other LLM services (such as Claude and Gemini) into the OpenAI format, it is necessary to create instances of the FunctionCall struct programmatically. However, the initializer for the FunctionCall struct is currently missing, making it impossible to create instances of this struct from code outside the package.

Affected Areas

Only ChatQuery.ChatCompletionMessageParam.ChatCompletionAssistantMessageParam.ChatCompletionMessageToolCallParam.FunctionCall

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud