Config diff should be smarter to detect the tools

[stof]

Currently, the diff is messy when a tool is disabled and another one is enabled because it does not consider a block as removed and the other block as added, but compares config of different tools together: https://scrutinizer-ci.com/g/Behat/Behat/inspections/1d22b986-1053-4a9b-9cd6-b24d8443d087/config/diff
This makes the diff totally useless (I'm quite sure the php_code_sniffer config is the same here).

and having all PHPCS rules rendered on a single line would make the diff useless as well when a rule is enabled, as it would mark the whole line as changed, forcing to diff by hand.