Sort imports from all files

Add "prettier" script in `package.json` to check if all files are
compliant.

Sort all imports and format all files by running `npm run lint -- --fix`
followed by `npm run prettier -- --write`.

Gitlab #29

Change-Id: Id80402d1344c3bc611f66a46cffeee5f2c375bd8
diff --git a/client/src/components/Message.js b/client/src/components/Message.js
index 7626c6e..0278d0b 100644
--- a/client/src/components/Message.js
+++ b/client/src/components/Message.js
@@ -5,6 +5,7 @@
 import isYesterday from 'dayjs/plugin/isYesterday';
 import React, { useCallback, useMemo, useState } from 'react';
 import { useTranslation } from 'react-i18next';
+
 import { EmojiButton, MoreButton, ReplyMessageButton } from './buttons';
 import ConversationAvatar from './ConversationAvatar';
 import { OppositeArrowsIcon, TrashBinIcon, TwoSheetsIcon } from './svgIcons';