Expose derivation hierarchy for profiles (and maybe other things?) in pre-publish phase

[lmckenzi]

When enforcing logic rules, it's useful to understand what the derivation hierarchy is for profiles (and possibly what the dependency hierarchy is for value sets). By default, a profile only shows its immediate parent, not all ancestors. Because information about ancestors often will only exist in dependency packages and not in the artifacts in an IG, there's no easy way for XSLT or Javascript in templates that's doing supplemental validation to access this information.

Propose that when converting all resources into XML & JSON form prior to generating artifacts that we inject a recursive extension on StructureDefinition.baseDefinition that allows traversing the 'ancestors' of the base and a similar extension on value set that declares dependency value sets and code systems. The IT template code could then leverage this information.