FEATURE(arborist) log warning when saving lockfile lacking resolved/integrity for non-bundled dependencies

[isaacs]

From npm/arborist#270

Reproduction case:

# reify to build package tree in node_modules
arborist reify

# remove all metadata about resolved/integrity
rm package-lock.json node_modules/.package-lock.json

# reify again to create a lockfile without full metadata
arborist reify # <-- this should warn

[isaacs]

Note: bundled deps should never have resolved/integrity values, because they weren't fetched by us, and can be literally anything.