Refacor electron app and add migrations

electron/cqrs/queries/handlers/getMessageById.ts

@@ -0,0 +1,11 @@
+import { DataSource } from 'typeorm';
+import { MessageEntity } from '../../../entities';
+import { GetMessageByIdQuery } from '../../types';
+import { rowToMessage } from '../../mappers';
+
+export async function handleGetMessageById(query: GetMessageByIdQuery, dataSource: DataSource) {
+  const repo = dataSource.getRepository(MessageEntity);
+  const row = await repo.findOne({ where: { id: query.payload.messageId } });
+
+  return row ? rowToMessage(row) : null;
+}