Add option for searching all typed keyword inside single category item record

I propose to add option (in administrative console) for searching (on Front-End) all typed keyword inside single category item record. For now if I type "test case" I will get all items, that contain "test" and all items, that contain "case". When I type "test case", then only items, that contain both keywords will be found. This new option will make search act like "" was used between all typed keywords.

This was implemented somewhere, by modifying kSearchHelper class.

This should be implemented as Config Option enabled by
default.