update to use sqlalchemy

- change from mysql-connector-python to sqlalchemy
    - allow for connection to sqlite3, mysql, mariadb, postgres, and
oracle databases
- change `DATE` columns to `DATETIME` type
- add WHO columns
- install database connectors and required packages

mpv-youtube-queue-server.service

@@ -10,10 +10,7 @@ Restart=on-failure
 Environment="MPV_SOCKET=/tmp/mpvsocket"
 Environment="LISTEN_ADDRESS=0.0.0.0"
 Environment="LISTEN_PORT=42069"
-Environment="MYSQL_HOST=http://localhost"
-Environment="MYSQL_USER=mpvuser"
-Environment="MYSQL_PASSWORD=SecretPassword"
-Environment="MYSQL_PORT=3306"
+Environment="DATABASE_URL=mysql+mysqldb://user:password@localhost:3306/mpv"
 
 [Install]
 WantedBy=multi-user.target