Be more helpful on unknown parameter messages

A user just had a case where they were getting

[ERROR] /usr/libexec/mysqld: unknown variable 'innobdb_lock_wait_timeout=1000'

due to the rather hard to spot extra b in innobdb.

Many other tools check such unknown values against a list of known one, e.g. comparing them via metrics like the Levenshtein distance, to add suggestions like:

unknown variable 'innobdb_lock_wait_timeout', did you mean 'innodb_lock_wait_timeout'?

I think this would be a great help and easy win.

(PS: I'm a bit biased about the Levenshtein distance as it was a key part of my original diploma thesis, and as I'm also responsible for having it in the PHP core)