Ability to exclude empty responses in fuzz mode

[Jaakkonen]

Some APIs always return same response status code and use empty response to tell from a error or from data not being found.

I'm thinking that the best way to work with this kind of endpoints is to have a exact --ignore-string flag which tests if the response body is exactly what is given.

Example rustbuster fuzz --ignore-exact "" -w wordlist.txt -u http://localhost:8000/api?field=FUZZ

A option to see response sizes in bytes like wfuzz gives also would address this use case when combined with grep by the user.