Consider deprecating or removing the enrichment module entirely

[JuxhinDB]

Currently the library is a mix between async and non-async modules. The permutation engine is trivial to use and integrate, making it pleasant to work with. The enrichment module however locks into a specified implementation which is (a) inflexible and (b) a pain to maintain.

After some thoughts, it seems that enrichment does not necessarily belong in the library at all, besides perhaps some traits to help library users extend the functionality to their liking.