fix: Ensure Message Send Requires Key 🔑 (#1281)

* fix: only allow message send when key is provided when required
- create useRequiresKey hook
- pass same disabled prop to Textarea, AttachFile, and SendButton
- EndpointItem: add localization, stopPropagation, and remove commented code
- separate some hooks to new Input dir
- completely remove textareaHeight recoil state as is not needed
- update imports for moved hooks
- pass disabled prop to useTextarea

* feat: add localization to textarea placeholders

client/src/hooks/Input/useRequiresKey.ts

@@ -0,0 +1,14 @@
+import { useGetEndpointsQuery } from 'librechat-data-provider';
+import { useChatContext } from '~/Providers/ChatContext';
+import useUserKey from './useUserKey';
+
+export default function useRequiresKey() {
+  const { conversation } = useChatContext();
+  const { data: endpointsConfig } = useGetEndpointsQuery();
+  const { endpoint } = conversation || {};
+  const userProvidesKey = endpointsConfig?.[endpoint ?? '']?.userProvide;
+  const { getExpiry } = useUserKey(endpoint ?? '');
+  const expiryTime = getExpiry();
+  const requiresKey = !expiryTime && userProvidesKey;
+  return { requiresKey };
+}