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/app/components/chatMessage/chatMessage.module.css

@@ -1,11 +1,6 @@
 div.chatMessageContainer {
     display: flex;
     flex-direction: column;
-    margin: 0.5rem;
-    padding: 0.5rem;
-    border-radius: 0.5rem;
-    border: 1px solid black;
-    /* max-width: 80%; */
 }
 
 div.you {
@@ -81,5 +76,5 @@ button.codeCopyButton:hover {
 
 div.feedbackButtons img,
 button.copyButton img {
-    width: auto;
+    width: 24px;
 }