Add support for URL input to Runtime Image

[malgamves]

Currently, running a generative search with an image input doesn't support URLs as in input parameter...

i.e

response = await myCollection.generate.nearText("Movies", {
  groupedTask: {
    prompt: "Which movie is closest to the image in terms of atmosphere",
    images: [base64String],      // A list of base64 encoded strings of the image bytes
    // imageProperties: ["img"], // Properties containing images in Weaviate
}
  config: generativeParameters.anthropic({
    maxTokens: 1000
  }),
}, {
  limit: 5,
})

Could we support having a list of URLs as an input.