Support for labels

[jyoo-mad]

Is your feature request related to a problem? Please describe.
As of 1.9, there is currently no support for labels

Describe the solution you'd like
I don't know the level of client-side validation the maintainers would like, but it could be as simple as adding the optional property to the GenerateContentRequest type as a Record<string, string> and passing it through here:

nodejs-vertexai/src/functions/generate_content.ts

Lines 72 to 80 in 31de0e9

	const generateContentRequest: GenerateContentRequest = {
	contents: request.contents,
	systemInstruction: request.systemInstruction,
	cachedContent: request.cachedContent,
	generationConfig: request.generationConfig ?? generationConfig,
	safetySettings: request.safetySettings ?? safetySettings,
	tools: request.tools ?? tools,
	toolConfig: request.toolConfig ?? toolConfig,
	};

You might also allow setting labels at the model-init level and overriding them in the method/request, based on the pattern seen in the code. Whatever the case for implementation, it would be nice to have labels supported by this client.