Anonymize flagged as spammer display names

[Redmak]

Whenever I flag a spammer certain actions are carried out to ban the account and IP and also soft delete their posts, but one thing that I think should be taken into consideration is freeing up display name choices of spammers. In many cases the names are now thought out well to try and bypass the antispam checks, meaning it is forever lost to genuine members registering later.

Simply: On flag as spammer, also randomize the member name to guest[number] similar to what the GDPR task does.

I currently am using 4.6.5.1.