Add dropzone for attachment, paste attachment from clipboard

client/src/hooks/use-modal.js

@@ -0,0 +1,15 @@
+import { useCallback, useState } from 'react';
+
+export default (initialParams) => {
+  const [modal, setModal] = useState(() => initialParams);
+
+  const open = useCallback((params) => {
+    setModal(params);
+  }, []);
+
+  const handleClose = useCallback(() => {
+    setModal(null);
+  }, []);
+
+  return [modal, open, handleClose];
+};