Implement support for koboldcpp SSE streaming.

koboldcpp added SSE streaming to its API as of:
https://github.com/LostRuins/koboldcpp/pull/220

This has not yet been added to release, but I figued I'd try to
get the work done to make it ready.

Work mostly hijacked from:
10bbc97069

server.js

@@ -381,33 +381,39 @@ app.post("/generate", jsonParser, async function (request, response_generate = r
     console.log(this_settings);
     const args = {
         body: JSON.stringify(this_settings),
-        signal: controller.signal,
         headers: { "Content-Type": "application/json" },
+        signal: controller.signal,
     };
 
-    const MAX_RETRIES = 10;
-    const delayAmount = 3000;
-    for (let i = 0; i < MAX_RETRIES; i++) {
-        try {
-            const data = await postAsync(api_server + "/v1/generate", args);
-            console.log(data);
-            return response_generate.send(data);
-        }
-        catch (error) {
-            // data
-            if (typeof error['text'] === 'function') {
-                console.log(await error.text());
-            }
+    try {
+        const fetch = require('node-fetch').default;
+        const url = request.body.streaming ? `${api_server}/extra/generate/stream` : `${api_server}/v1/generate`;
+        const response = await fetch(url, { method: 'POST', timeout: 0, ...args });
+        console.log(response);
+        if (request.body.streaming) {
+            // Pipe remote SSE stream to Express response
+            response.body.pipe(response_generate);
 
-            // response
-            switch (error.statusCode) {
-                case 503:
-                    await delay(delayAmount);
-                    break;
-                default:
-                    return response_generate.send({ error: true });
-            }
-        }
+            request.socket.on('close', function () {
+                response.body.destroy(); // Close the remote stream
+                response_generate.end(); // End the Express response
+            });
+
+            response.body.on('end', function () {
+                console.log("Streaming request finished");
+                response_generate.end();
+            });
+        } else {
+            if (!response.ok) {
+                console.log(`Kobold returned error: ${response.status} ${response.statusText} ${await response.text()}`);
+                return response.status(response.status).send({ error: true });
+             }
+
+            const data = await response.json();
+            return response_generate.send(data);
+         }
+    } catch (error) {
+        return response_generate.send({ error: true });
     }
 });