Add a fact checker feature with updated styling (#835)

- Add an experimental feature used for fact-checking falsifiable statements with customizable models. See attached screenshot for example. Once you input a statement that needs to be fact-checked, Khoj goes on a research spree to verify or refute it.
- Integrate frontend libraries for [Tailwind](https://tailwindcss.com/) and [ShadCN](https://ui.shadcn.com/) for easier UI development. Update corresponding styling for some existing UI components. 
- Add component for model selection 
- Add backend support for sharing arbitrary packets of data that will be consumed by specific front-end views in shareable scenarios

src/interface/web/next.config.mjs

@@ -31,7 +31,16 @@ const nextConfig = {
                 protocol: "https",
                 hostname: "assets.khoj.dev",
             },
-        ] : undefined,
+        ] : [
+            {
+                protocol: "https",
+                hostname: "*"
+            },
+            {
+                protocol: "http",
+                hostname: "*"
+            }
+        ]
     }
 };