Add a comparator that allow to give control on test to indicate if 2 objects are equals. This comparator have also a diff context that can be helpful to know which objects are compared.
FIX: don't fail when failing to load cold classes
Merge branch 'json-diff-comparator' of https://github.com/driccio/restx into driccio-json-diff-comparator
review how json comparator is stored
introduce AutoPreparable components

an additional step in factory / requests lifecycle, useful for very lightweight components
which have to be prepared once.

This prevents using router for components that need to be initialized per request in dev mode
but aren't actually involved in the routing mechanism.