Consider upgrading to mysql2 instead of mysql

[Apollon77]

... because mysql seems to be unmaintained and do not support MySQL 8 encryption schemas. mysql2 package seems to be a drop in replacement

[Apollon77]

Tried it and seems to work. should I do a PR for it?

[Apollon77]

In fact the mysql2 library is a drop In replacement with ths only difference that it do not like additional keys in the options object.

my try-out solution is this: to remove all fields that might be in because of sql-client ... https://github.com/ioBroker/ioBroker.sql/blob/master/lib/mysql-client.js#L16-L22 ... I'm no real coffeescript coder, so no idea if I need to do it differently there?