Implement missing API check functions for Arabica/Core

Implement missing api_core_check...() functions. Currently many of them naively assume everything is fine and return true, instead of actually doing some required checking first.

LONI Pipeline library handling for Arabica/Core

Implement LONI Pipeline server and personal library support. This requires new API functions that deal with converting internal modules, templates and wizard outputs into external format and writing into specified directory.