Load a package colspec to case

The package colspec may be consumed by link_col2doc(), in order to link column names to their metadata. If lookup_cache is NULL/empty, a new one will be made.

load_package_colspec(pkg_name, lookup_cache = NULL)

Arguments

pkg_name	the name of the package from which the set of columns should be loaded.
lookup_cache	the storr::storr object, generated by load_package_colspec(), containing keys (given by column aliases) mapping to column metadata lists.