cli: Send all images in conversation history

Currently the CLI only sends images from the most recent image-
containing message. This prevents doing things like sending
one message with an image and then a follow message with a
second image and asking for comparision based on additional
information not present in any text that was output.

It's possible that some models have a problem with this but the
CLI is not the right place to do this since any adjustments are
model-specific and should affect all clients.

Both llava:34b and minicpm-v do reasonable things with multiple
images in the history.

cmd/interactive.go

@@ -442,13 +442,6 @@ func generateInteractive(cmd *cobra.Command, opts runOptions) error {
 					return err
 				}
 
-				// clear all previous images for better responses
-				if len(images) > 0 {
-					for i := range opts.Messages {
-						opts.Messages[i].Images = nil
-					}
-				}
-
 				newMessage.Content = msg
 				newMessage.Images = images
 			}