Add command for data deletion request

[laggron42]

The goal is to add a command such as /player deleteme that would delete the Player row and cascade on the caught balls.

It must have big warning to explain that this is irreversible.

Needed for GDPR compliance.

[flaree]

I'm going to assign to myself as I would like to also add an export command which I already have prepared from evals within the server