New rule: Ban files

[illia-romanenko]

I want to have a rule to check that my project doesn't contain specific files (like .env files for example) as well as for some files I want to make sure that even if they do exist I can insert regexp of content - so it can validate content based on that regexp.

[illia-romanenko]

@solid-maksymtielnyi mentioned that there could be cases with .env files contain mixed data - secure keys or public information like URL (like base api url), that don't require protection, so we can think of regexp or customized implementation that can ignore certain rows. So we need to decide whether regexp for whole file or per row in that case.