Merge pull request nestjs#8845 from Tony133/sample/update-dependecie-mysql8

sample(05-sql-typeorm): update dependecie for mysql 8.x and some improvements

Author: kamilmysliwiec

sample/05-sql-typeorm/package-lock.json

@@ -23,7 +23,7 @@
     "@nestjs/core": "8.2.3",
     "@nestjs/platform-express": "8.2.3",
     "@nestjs/typeorm": "8.0.2",
-    "mysql": "2.18.1",
+    "mysql2": "2.3.3",
     "reflect-metadata": "0.1.13",
     "rimraf": "3.0.2",
     "rxjs": "7.4.0",