[Feature]: Unify Setting Key and Path

[cancan101]

Feature description

Currently the Path is specified on the "Resolver":

but the Key is specified as a Mapping:

I suggest adding the ability to set the Path using the mapping as well. This would (a) allow for consistency of config and more importantly (b) allow using the transforms to compose the path. Currently we ave to maintain logic outside of the importer since the path needs to be a specific field in the file.

[fashxp]

I like the idea, but isn't the mapping (as it is right now) too late for the path as the path is needed during resolving?

Probably we would need a resolver strategy that also provides (at least a subset) of the mapping functionality?