RFE: prohibit use of grep in boolean context

[scop]

Similarly as the nice ProhibitGrepToGetFirstFoundElement, it would be nice to have a check that looks for use of grep to check if an element exists, i.e. in boolean context.

When found, it would advise to use List::Util::any() (or ::none() when inverted) instead, mainly for performance but arguably for semantic reasons, too.

Perhaps call it ProhibitGrepToCheckIfElementExists or ProhibitGrepInBooleanContext.