blueprint apply definition lookup error

[MicroProofs]

When trying to apply some parameters we kept facing this error.

Upon further inspection is seems like lookup was using Reference::as_key which returns the definition ref with ~1. The definitions map does not contain keys in that format, the keys in this map use / instead of ~1.

We've updated as_key to always replace ~1 with / so that lookups work as expected.

[KtorZ]

I think that should work. Indeed, in the JSON schema, the definitions keys will be using / whereas the pointers references will be using ~1.