Initial commit: add a dedicated page for managing the knowledge base

- One current issue in the Khoj application is that managing the files being referenced as the user's knowledge base is slightly opaque and difficult to access
- Add a migration for associating the fileobjects directly with the Entry objects, making it easier to get data via foreign key
- Add the new page that shows all indexed files in the search view, also allowing you to upload new docs directly from that page
- Support new APIs for getting / deleting files

src/interface/web/app/components/appSidebar/appSidebar.tsx

@@ -17,7 +17,7 @@ import {
     KhojSearchLogo,
 } from "../logo/khojLogo";
 import { Gear } from "@phosphor-icons/react/dist/ssr";
-import { Plus } from "@phosphor-icons/react";
+import { Book, Plus } from "@phosphor-icons/react";
 import { useEffect, useState } from "react";
 import AllConversations from "../allConversations/allConversations";
 import FooterMenu from "../navMenu/navMenu";
@@ -26,6 +26,7 @@ import { useIsMobileWidth } from "@/app/common/utils";
 import { UserPlusIcon } from "lucide-react";
 import { useAuthenticatedData } from "@/app/common/auth";
 import LoginPrompt from "../loginPrompt/loginPrompt";
+import { url } from "inspector";
 
 // Menu items.
 const items = [
@@ -54,6 +55,11 @@ const items = [
         url: "/settings",
         icon: Gear,
     },
+    {
+        title: "Knowledge Base",
+        url: "/knowledge",
+        icon: Book,
+    },
 ];
 
 const SIDEBAR_KEYBOARD_SHORTCUT = "b";