Add support for the ext::ai embeddings API

[scotttrinh]

It should decode the embeddings from the extension response so that it can be provided directly to the ext::ai::search method.

[scotttrinh]

Done!

edgedb-js/packages/ai/src/core.ts

Lines 175 to 197 in fb64e3c

	async generateEmbeddings(inputs: string[], model: string): Promise<number[]> {
	const response = await (
	await this.authenticatedFetch
	)("embeddings", {
	method: "POST",
	headers: {
	"Content-Type": "application/json",
	},
	body: JSON.stringify({
	model,
	input: inputs,
	}),
	});
	if (!response.ok) {
	const bodyText = await response.text();
	throw new Error(bodyText);
	}
	const data: { data: { embedding: number[] }[] } = await response.json();
	return data.data[0].embedding;
	}
	}