Fix uploads for non-admin users

frontend/src/app.ts

@@ -43,6 +43,10 @@ class App {
   isLoggedIn() {
     return this.user != null && this.token != null;
   }
+
+  canUpload() {
+    return this.isLoggedIn() && (this.user?.can_upload || this.isAdmin());
+  }
 }
 
 export const app = new App();

frontend/src/pages/publish_page.tsx

@@ -94,7 +94,7 @@ export default function PublishPage() {
     return <ErrorAlert className={"m-4"} message={t("You are not logged in. Please log in to access this page.")} />
   }
 
-  if (!app.user?.is_admin) {
+  if (!app.canUpload()) {
     return <ErrorAlert className={"m-4"} message={t("You are not authorized to access this page.")} />
   }
 

frontend/src/pages/resource_details_page.tsx

@@ -272,7 +272,7 @@ function Files({files, resourceID}: { files: RFile[], resourceID: number }) {
     }
     <div className={"h-2"}></div>
     {
-      app.isAdmin() && <div className={"flex flex-row-reverse"}>
+      app.canUpload() && <div className={"flex flex-row-reverse"}>
         <CreateFileDialog resourceId={resourceID}></CreateFileDialog>
       </div>
     }