Ensure nodetype definitions are only (re)loaded when the cnd resource file has been changed

The current implementation in ConfigurationConfigService#applyNodeTypes does blind reload of all the provided CNDs at startup.

However, this can cause production problems, see: REPO-439

So for HCM we need to implement a similar protection against reloading cnds unless they actually have been changed.

The simplest solution for this may be to explicitly store a digest for cnd resources in the baseline, and simply compare against this at startup.