Split `payload`-typedef variant into two separate types: eg `MemoryRegion` and `CheckerResult`

[kusnezoff-alexander]

eg

using MemoryRegion = std::span<std::byte,>,;
using CheckerResult = std::pair<bool, Reason>;

• modify logger.call() and recipe.next() to work with types appropriately
• delete ::CHECK from enum Actions bc it is only the purpose for distinguishing btw both variants in Payload ?